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Car Forum / Honda Cars / November 2005Hybrids - Toyota vs Honda
Excerpts from http://www.businessweek.com/magazine/content/05_46/b3959057.htm While the Toyota Prius sells in eight days, the Honda Accord hybrid takes some two months to exit the lot. The Honda Civic hybrid is no Prius either - it takes 36 days to move. Clearly, the Prius's conspicuous display of uber-greenness is key to its success. But it also features a radically new driving experience. It's quite a thrill to hit the accelerator and slip along in near silence. Not so for Honda hybrids. Because the gasoline engine is working most of the time - getting an electrical boost during acceleration - it drives much like a regular car. Honda says its technology is fuel efficient and cheaper, but that may not be enough to wow drivers. *************************************************** Drawing on my fine command of the English language, I said nothing. ...Robert Benchley : Honda says its technology is fuel : efficient and cheaper, but that may not be enough to wow drivers. Honda missed the point. Their hybrid just too ugly - and the blame falls partly on that funky looking, fender-covered thing they tried to peddle (the Insight??). Mack >: Honda says its technology is fuel > : efficient and cheaper, but that may not be enough to wow drivers. [quoted text clipped - 3 lines] > Their hybrid just too ugly - and the blame falls partly on that funky > looking, fender-covered thing they tried to peddle (the Insight??). That may be true for the Insight, but the Civic and Accord Hybrids look just like regular Accords and Civics. Persoanlly, I think the Toyota system is superior, although I remain unconvinced that I really care that much about hybrids in general. However, I think the size of the Prius, and the very positive press are major factors contributing to it sales sucess. Also the distinctive, if unual styling lets the world know that the driver really cares about the environment. The enviromentalist driving a Civic Hybrid might not get noticed.... Insight (CVT) - 57 City / 56 Hwy / 56 combined Insight (manual) - 60 City / 66 Hwy / 63 combined Civic Hybrid - 49 City / 51 Hwy / 50 combined Prius - 60 City / 51 Highway / 55 combined Accord Hybrid (2005) - 29 City / 37 Hwy / 32 combined Ford Escape (FWD) - 36 City / 31 Hwy / 33 combined Toyota Highlander Hybrid (FWD) - 33 City / 28 Hwy / 30 combined Toyota Camry (4 cylinder, 5 sp manual) - 24 City / 34 Hwy / 28 combined Ed Perhaps they don't want to stand out as not being a very astute buyer who fell for the hybrid hype? ;) mike hunt >>: Honda says its technology is fuel >> : efficient and cheaper, but that may not be enough to wow drivers. [quoted text clipped - 15 lines] > noticed.... > Ed I suppose the reason is the Civic buyer can get a better perspective on the premium price one must pay to buy a hybrid when looking at the came car with the different power plants. That premium will buy nearly ALL of the fuel for a conventional powered Civic. In the case of the Prius most buyers do not think to compare it to the Corolla for size, price, and fuel mileage. To say nothing of the fact dealers never mention the huge battery replacement cost somewhere down the line. mike hunt > Excerpts from > http://www.businessweek.com/magazine/content/05_46/b3959057.htm [quoted text clipped - 18 lines] > > ...Robert Benchley >I suppose the reason is the Civic buyer can get a better perspective on the >premium price one must pay to buy a hybrid when looking at the came car with [quoted text clipped - 3 lines] >To say nothing of the fact dealers never mention the huge battery >replacement cost somewhere down the line. You know, I've heard this comment about battery life and huge battery replacement cost before. So I'm curious, just how long is the life expectancy of a hybrid battery? Would that mean that the resale value of a used hybrid would drop faster with time than a similar model non-hybrid? CD > You know, I've heard this comment about battery life and huge battery > replacement cost before. So I'm curious, just how long is the life [quoted text clipped - 3 lines] > > CD It is a good question and one which I suspect the car makers know the answer to, but are keeping quiet about. The battery technology being used is a larger implemenation of the same rechargeable battery types already deployed in laptops, cordless power tools, digital cameras, cell phone and the like. I have had more laptop batteries totally fail to take a charge than I would care to think about. They typically work great at first, but months or years down the line need to be replaced at a high cost. With cordless power tools (drills, etc.) it is often cheaper to buy a whole new one than it is to replace the power packs. Typically a couple of years of moderate use is all it takes for those battery packs to be worthless. Lithium batteries, for example, are generally rated for 300-500 charge-discharge cycles before being useless. Typically as the number of cycles adds up, the capacity deteriorates. See: http://www.batteryuniversity.com/parttwo-34.htm Nicad batteries are generally considered usefull for around 700 carefully managed cycles. See: http://www.directron.com/batteryterms.html I believe that the Prius and other presently available hybrids use Nicad for this longer cycle life, even though Lithium batteries offer a higher power density. There are no 5-10 year old Nicad laden cars on the road right now, so only time will tell. My guess is that somewhere around 2009-2010 there are going to be a bunch of surprised and angry customers, many of them the second owners of these vehicles. John > There are no 5-10 year old Nicad laden cars on the road right now, so > only time will tell. My guess is that somewhere around 2009-2010 there > are going to be a bunch of surprised and angry customers, many of them > the second owners of these vehicles. A google search using hybrid battery replacement reveals much. The consensus of many critics seems to be that hybrids, for the price, are not yet cost effective and are now just a "feel good" car for well off tree huggers. nb >A google search using hybrid battery replacement reveals much. The >consensus of many critics seems to be that hybrids, for the price, are >not yet cost effective and are now just a "feel good" car for well off >tree huggers. The hybrids have never been cost effective, pretty much everyone agrees on that. ===================== Fallacies do not cease to be fallacies because they become fashions. ...G.K. Chesterton >> You know, I've heard this comment about battery life and huge battery >> replacement cost before. So I'm curious, just how long is the life [quoted text clipped - 36 lines] > going to be a bunch of surprised and angry customers, many of them the > second owners of these vehicles. The Prius does not use NiCads. It uses nickel-metal hydride (NiMH) batteries. And the Prius system only discharges htem to about 80% of capacity. These batteries have very good life, and the limited dicharge enhances this further. I believe that in normal usage, you can expect the battery to last 150,000-200,000 miles. http://www.peve.panasonic.co.jp/catalog/e_kaku.html http://www.eng-tips.com/viewthread.cfm?qid=135399&page=1 http://www.lubbockautos.com/autonews/toyota/062204.shtml Ed No matter how one choose to spin it, the Prius will need a new battery pack at some point in its life and the cost at that time will be so high, in comparison to the value of the vehicle, that its value with spent batteries will by virtually nothing. Who is going to foolish enough to replace a $4,000 battery pack in a $4,000 vehicle? mike hunt >>> You know, I've heard this comment about battery life and huge battery >>> replacement cost before. So I'm curious, just how long is the life [quoted text clipped - 49 lines] > > Ed > No matter how one choose to spin it, the Prius will need a new battery > pack at some point in its life and the cost at that time will be so high, [quoted text clipped - 3 lines] > > mike hunt I don't think that is a safe conclusion at all. With a number of Prius approaching the 200K mile and 5 year mark, there have been few enough outright battery failures that validating them is difficult (obvious hoaxes are common). It is more likely as Toyota indicates; most will never need a replacement battery. If somebody does need one, used batteries are often offered for $400-$1000 US on ebay, courtesy of road accidents. To test the battery, the multi-function display includes a diagnostic screen that reports individual cell health (one of those secret sequence things) and the cells are individually replaceable. Every vehicle dies of something. I've scrapped a Mercury Capri because it needed a new driveshaft (integral u-joints!) and the price was over $200. To assume HV batteries will be the death of most hybrids is quite a stretch, especially given their track record. Mike > [re Prius main battery] To test the battery, the multi-function > display includes a diagnostic screen that reports individual > cell health (one of those secret sequence things) and the cells > are individually replaceable. Can you pass on the sequence, please? I'd love to have it handy for my UK-spec T4 Prius (new Aug 2005), for occasional checking. More generally: there are so many ignorant people, ready to make sweeping and ignorant statements about hybrids that I've learned to disregard them, or (for fun) pick out the weasel-phrases used to insure against contradiction. The bleeding things work, now. I am assuming Toyota (with Honda, and whoever else undertakes to manufacture advanced vehicles) do accelerated life testing &c &c with a view to ensuring customers don't get mightily cheesed off before they've had value for money. Time, not ignorant opinion, will tell. FWIW my Toyota dealer tells me today that the UK price for a new main Prius battery (w/o labour charges or taxes) is GBP 1321.35, which I hope helps to focus the discussion. (Side note: earlier this year I posted a substantially lower price, also supplied by my dealer; but I think he must have misunderstood the question.) I would expect this price to fall as design refinements are made and production ramps up -- what to, who knows.  SignatureAndrew Stephenson > More generally: there are so many ignorant people, ready to make > sweeping and ignorant statements about hybrids that I've learned > to disregard them, or (for fun) pick out the weasel-phrases used > to insure against contradiction. The bleeding things work, now. But what problems do they solve, and what other solutions are there for the same problems? They solve exactly one problem: recapturing braking energy to re-use on acceleration. There's only one place where that works: city driving. The requirement for braking came from the burning of petrol to create acceleration in the first place. Must we burn petrol to create the acceleration? Can anything else solve that problem? They're also more expensive to make and to buy. That's a problem in and of itself. If we're trying to save on petrol, can we use any other motive source for acceleration? If so, can that other motive source be purchased cheaper than the hybrid? For example: can a diesel engine solve the problem better/cheaper/more reliably than a hybrid? Can I run a diesel and spend less money, or no more than the same money, as a hybrid? Let's say I spend the exact same amount of money per mile to motivate the diesel as the hybrid. Now it comes down to maintenance and reliability. Is the diesel cheaper or more expensive to maintain? What about the reliability--can I get the diesel fixed cheaper? What happens when I go out in the country somewhere--can I rely on the magic black box of software that the hybrid depends upon, or will a diesel be more reliable because it doesn't depend on a computer just to run? There are so many questions to ask yourself once you dig down. I prize reliability and simplicity. The Toyota hybrid fails the simplicity test horribly, the Honda hybrid much less so, the diesel virtually not at all. And frankly, it's all about MY pocketbook. Which one, over 200K miles, cost me the least out of pocket to buy, maintain, repair, and insure? > > More generally: there are so many ignorant people, ready to make > > sweeping and ignorant statements about hybrids that I've learned [quoted text clipped - 3 lines] > But what problems do they solve, and what other solutions are there for > the same problems? At the risk of turning this into one of those endlessly circling threads, I'll try to go through your points, which are reasonable but based (in a couple of places at least) on insufficient facts. All of the following is AFAIK, okay? At this stage in the development of hybrids and advanced vehicle design in general, the industry is having to play catch-up after decades of, frankly, unforgivable negligence. Now that pressure is on to make best use of resources, they are seeking answers. So these vehicles are, to some extent, test beds. The initial experiments have been done at the factory and have reached the stage where the product is deemed good enough to be released for long-term market testing. As with ANY product, there will be imperfections, which we hope will be removed by re-design. The main problems the Prius (and, I assume, competing designs) is _trying_ to solve seem to fall into at least three areas: better conversion of the fuel (petrol/gas/&c) into a form useful within the vehicle (eg, movement, light, heat, communications); reduced waste of same thereafter; improved control generally to make the car more efficient (re: energy) and a good drive (eg, responsive, surer-footed on slippery surfaces, positive steering+braking). On top of those perfomance-related issues, there is the question of improving the vehicle's green credentials. Now, I know that for some people "green" is a red-rag-to-a-bull trigger word. By it, I mean "how to reduce the amount you throw away needlessly". Manufacturers are learning to waste less whilst building the car, waste less whilst it's working, recover more when it's scrapped. It's not a political question, unless we insist on making it so. Saving makes such bleeding obvious sense, I'll stop beating that drum right there. > They solve exactly one problem: recapturing braking energy to > re-use on acceleration. There's only one place where that > works: city driving. Well, no, they already solve more problems than that. The Prius uses several tricks to cut fuel consumption. The regenerative braking is significant, certainly; but the greater effiiency of the Atkinson engine (less power for the same capacity, but much greater efficiency) is the first major plus. Then, yes, waste due to braking counts for a lot. On top of that, the electric motor does a better job of start/slow/stop movement than a plain old ICE would, as technology stands now. Finally, there is the control system, which works behind the scenes, choosing optimal strategies as best it can. > [...] > > They're also more expensive to make and to buy. That's a > problem in and of itself. If we're trying to save on petrol, can > we use any other motive source for acceleration? A dangerous generalisation. The Prius has bits conventional cars lack, yes (eg: battery, electric generator and motor, inverter, planetary gear), but lacks some conventional parts (eg: clutch, gearbox); and some parts are simplified or smaller (eg: 1.5 litre petrol engine, 45 litre fuel tank, lightweight transmission). A slew of parts are entirely conventional and can benefit from past developments and existing production methods (eg: wheels+tyres, suspensions, hydraulic brake components (augmented by regen.), lights, seating, steering, structure parts, body panels, paint and plastics bits). Get the idea? It's a trade-off. And, to repeat something that really shouldn't need repeating, in an age when we trust horrendously complex gadgets with our lives every hour: complexity does not have to mean unreliability. The Prius braking system, for example, is full of feedback loops that cope with small failures. Go look it up: Toyota are fairly free with their literature and sent me detailed techical info. > If so, can that other motive source be purchased cheaper than > the hybrid? It'll be something that surprises us -- count on it. > For example: can a diesel engine solve the problem > better/cheaper/more reliably than a hybrid? Time will tell. My money is on someone developing a diesel that can be fitted into a hybrid, thereby gaining the best of both. > There are so many questions to ask yourself once you dig down. Indeed. I totally agree with you there. > And frankly, it's all about MY pocketbook. Which one, over > 200K miles, cost me the least out of pocket to buy, maintain, > repair, and insure? One of the nice aspects of a free market is that _you_ can choose not to participate in the Great Experiment. With more of us out there, trying alternative solutions, we may find a better way a lot sooner. So go for it. Or not. Thus far, I like my Prius. It cost me significantly less (purchase price) and serves me more to my taste than some quite swanky cars I looked at. SignatureAndrew Stephenson > > But what problems do they solve, and what other solutions are there for > > the same problems? [quoted text clipped - 4 lines] > > All of the following is AFAIK, okay? Good discussion, thanks. > Now, I know that > for some people "green" is a red-rag-to-a-bull trigger word. By > it, I mean "how to reduce the amount you throw away needlessly". > Manufacturers are learning to waste less whilst building the car, > waste less whilst it's working, recover more when it's scrapped. That pretty much sums it up. "Green" isn't a car, it's a holistic philosophy. > Finally, there is the > control system, which works behind the scenes, choosing optimal > strategies as best it can. Personally, I have trouble evaluating the control system in a vacuum. I need to evaluate the benefits of the control system against the cost of the fact that the control system is incredibly complex--and complexity brings its own set of problems to the table. Now we're into the law of unintended consequences. > The Prius has bits conventional cars > lack, yes (eg: battery, electric generator and motor, inverter, > planetary gear), but lacks some conventional parts (eg: clutch, > gearbox); Many cars can use less complex transmissions as well. That they don't choose to is another matter. > And, to repeat something that really shouldn't need repeating, in > an age when we trust horrendously complex gadgets with our lives > every hour: complexity does not have to mean unreliability. Pull back a bit, and see what happened when a hurricane hit our incredibly complex and teetering on the edge energy market. Complexity puts you that much closer to the edge. > > For example: can a diesel engine solve the problem > > better/cheaper/more reliably than a hybrid? > > Time will tell. My money is on someone developing a diesel that > can be fitted into a hybrid, thereby gaining the best of both. That's such a simple concept, I'm amazed it hasn't been done. Didn't I read in Car and Driver magazine some time ago that an idling diesel engine consumes virtually no fuel? This was in regard to big rig trucks, but still. The question came up about why truck drivers don't shut their engines off in situations where car drivers would, and that was the answer. > Thus far, I like my Prius. > It cost me significantly less (purchase price) and serves me more > to my taste than some quite swanky cars I looked at. Frankly, if anyone can do it it'll be Toyota. I find it mildly humorous that Ford has licensed Toyota hybrid technology for their Escape... You forgot one very impotent part of that equation....REPLACEMENT cost. The hybrids, all of them, cost more to buy than conventionally power vehicles of the same size and equipment. They will cost more to replace as well. Especially if the batteries are depleted. The fact is the premium one pays to acquire a hybrid will generally buy ALL of the fuel, used by a comparable conventionally power vehicle, for three to four years. For the average new car buyer in the US that replaces their new vehicle with another new vehicle in three to four years that can mean all of the fuel for as long as they generally own their vehicles. Personally I hope more buyers choose hybrids to save the planet, that will stretch the supply of fuel for those of use that prefer high powered, safer, large vehicles. The only problem I see is if the consumption of fuel, in total, is going down the price of fuel will rise for those that have trouble buying fuel at todays prices evn for hybrid owners. ;) mike "Elmo P. Shagnasty" > And frankly, it's all about MY pocketbook. Which one, over 200K miles, > cost me the least out of pocket to buy, maintain, repair, and insure? > to acquire a hybrid will generally buy ALL of the fuel, used by a comparable > conventionally power vehicle, for three to four years. Probably closer to 8 years, the life expectency of a hybrid battery pack. > For the average new > car buyer in the US that replaces their new vehicle with another new vehicle > in three to four years that can mean all of the fuel for as long as they > generally own their vehicles. Or longer. > Personally I hope more buyers choose hybrids > to save the planet.... I'm not. It's a diversion from hydrogen technology. Besides, battery production is an incredibly toxic industry. Your trading one plague for another. nb hybrids don't just work by capturing braking energy. They run a more fuel efficient cycle with a longer expansion stroke. The Miller/Atkinson cycle. They can do this because acceleration is supplemented by the battery. They also have a smaller engine b/c it can use batteries to accelerate. By using the Miller cycle they get a higher % of energy out of the gas and into the drivetrain. It's very ingenious. Hydrogen is probably never going to "be here". You need a fuel source to get hydrogen. Hydrogen is very hard to transport (harder than natural gas which is difficult enough) and there are no cheap "fuel cells". The advantages of a liquid fuel are great. I think the next step is using a smaller gas engine and a larger/cheaper battery that you can plug in. You could plug it in for an hour a night and that would take you maybe 30-40 miles. On longer trips and under acceleration the gas engine would turn on. That way you'd be replacing gas with electricity, which can come from nuclear/coal/wind whatever. > But what problems do they solve, and what other solutions are there for > the same problems? > > They solve exactly one problem: recapturing braking energy to re-use on > acceleration. There's only one place where that works: city driving. Regenerative braking is very far down on the list of values in hybridization. The essential purpose is to use the primary power source more efficiently. Putting a 240 hp engine in a passenger car to cruise around town at 35 mph is extremely inefficient. Using a 50 hp engine to do that is far more efficient, but responsiveness suffers badly. We are in the infancy of hybridization now, but as the power technology advances a 50 hp hybrid can be more efficient than a 50 hp conventional car and provide better responsiveness than a 240 hp conventional car. The difference is made up by stored electric power. In actuality, a car would have to be pretty small to warrant only a 50 hp engine. The design becomes straightforward, though. The power necessary to climb a 6% grade at the prevailing maximum speed (75 mph in the US) at maximum gross weight is exactly the engine power needed. For a mid-size car that is in the 100 hp range, maybe slightly less. The side effects of running the engine at higher power levels are valuable, too. Hybridization increasingly separates the engine from the driver control, so there are no issues with suddenly mashing the accelerator. Emissions are much easier to control as the engine comes under computer control. I can understand why there isn't a lot of enthusiasm for the current generation of hybrids. Not only do they have a limited track record, the level of hybridization is not enough to knock anybody's socks off. (Well, mostly not. See Honda's DualNote http://world.honda.com/Tokyo2001/auto/DUALNOTE/ for a glimpse of what is possible.) Mike >>But what problems do they solve, and what other solutions are there for >>the same problems? [quoted text clipped - 11 lines] > responsiveness than a 240 hp conventional car. The difference is made up by > stored electric power. One problem with that is the fact that the stored electric power eventually runs down. It would not be fun to be in the passing lane on a long uphill section of road going around a vehicle only to discover that your battery storage has just been exhausted and that the available torque is suddenly reduced 50%. Yikes! One thing hybrids bring into the equation is a significant depenence on near term prior history to a degree which conventional engines do not. John >>>But what problems do they solve, and what other solutions are there for >>>the same problems? [quoted text clipped - 22 lines] > > John It's all a matter of design. In your example, a properly designed hybrid will not run out of passing power because the engine power was enough to maintain full legal speed, while passing power is available because it was not needed to reach the cruising speed. A major reason multi-hundred horsepower engines are used in passenger cars today is to provide that margin, in spite of the economy penalty the vast majority of the time. Even in the previous generation Prius - the one we have - our battery has never dropped to "empty" (actually something like 50% charge) although we live at 7000 feet and have made trips with ful load to Washington state and the LA area. I've never heard anybody complain about that happening, either. It just isn't a problem. Mike >>>>But what problems do they solve, and what other solutions are there for >>>>the same problems? [quoted text clipped - 37 lines] > > Mike I wasn't talking about the Prius, I was talking about your hypothetical vehicle which you say would have a much smaller conventional engine than does a Prius. John >> It's all a matter of design. In your example, a properly designed hybrid >> will not run out of passing power because the engine power was enough to [quoted text clipped - 16 lines] > > John Right - the basic principle is to size the engine for the largest continuous output power required. Making it smaller will cause exactly what you describe (running out of power on long, hard uphill slopes) while making it larger is just a waste. Making a hybrid with a 50 hp engine (as I used as an earlier example) works just fine in the flatlands but would get a poisonous reputation for more general use. I used 50 hp as an example for the illustration of moving a car around in town in comparison with using a 240 hp engine. I realize in looking back that confused the issue. Sorry about that. It is useful to note that the driver wouldn't necessarily notice the difference in performance between a 50 hp engine and a 100 hp engine except for the hill climbs. Mike Not necessarily. It would depend at what RPMs each engine produced its maximum torque. It is after all tongue, not HP, that get the vehicle going from a stop and what keeps it going, at speed, up a long grade. The Pruis uses the electric motor when staring and adds it on grades because electric motors develop their greatest amount of tongue at start up. That is why most Toyota are under powered, compared to many of its competitors vehicles. . Toyota, like many import brand engines are designed to produce their HP at higher RPMs than the engines in domestic brands, that is why they run out of tongue rather quickly at speed.. The reason is domestics sell mostly automatic tyrannies in the majority of their vehicles that are equipped with tongue converters. On the other hand Japanese brands which use the same engines in cars sold in other countries that have a much larger percentage of their vehicle equipped with manual tyrannies. With a manual tranny the gear selector can be used to stay on the tongue curve to climb grades, particularly long grades. Most drivers of automatics are want to run their cars in the lower gears to stay on the tongue curve. Follow a Corolla equipped with a manual tranny up a long grade and it will quickly drop off the prevailing speed, unless the drive reverts to lower gears. Follow one with an automatic and you will see it runs out of gears trying to maintain speed, and the speed quickly drops off, because few drivers are willing to run their engines at the much higher RPMs in lower gears needed to maintain the prevailing speed. mike hunt "Michael Pardee" . Sorry about > that. It is useful to note that the driver wouldn't necessarily notice the > difference in performance between a 50 hp engine and a 100 hp engine > except for the hill climbs. > > Mike > Not necessarily. It would depend at what RPMs each engine produced its > maximum torque. It is after all tongue, not HP, that get the vehicle [quoted text clipped - 20 lines] > > mike hunt In a serial hybrid (which does not yet exist in mass production) there are no gearing issues because the engine only drives a generator, and the electricity powers the car. We don't have the power electronics yet for serial hybrids, but another decade should get us there. (Getting back to the subject line...) Presently, Honda's hybrids are what are usually called parallel hybrids. The power train is conventional except that the engine is assisted (Honda calls it Integrated Motor Assist, or IMA) by the electrics. Toyota uses an inventive scheme they call "series-parallel," where a part of the engine torque is directed to the wheels and part is used to generate electricity to power the electric motor. That's why the Prius has no transmission per se (and can't have one), just a skewed differential and a pair of motor/generators. They call it an Electronic CVT. On hard uphill climbs the engine runs up to the maximum engine speed (4500 rpm in the pre-2004s, 5000 rpm in the current ones IIRC) and puts out full rated power with a minimum of drama, completely independent of the car's speed. At lesser power requirements the hybrid computer adjusts the load on the generation part to control the load on the engine, so all aspects of the engine operation are under computer control: mixture, ignition and valve timing, throttle and load... even whether the engine is running or not. Mike > Not necessarily. It would depend at what RPMs each engine produced its > maximum torque. It is after all tongue, not HP, that get the vehicle going [quoted text clipped - 3 lines] > most Toyota are under powered, compared to many of its competitors > vehicles. They're not underpowered. You might try surprising us with facts for a change. But I doubt you will. I drove through CO, UT, AZ and NM last spring in my '01 Sienna. 5 passengers and camping equipment and it never dowhshifted on all the freeways through the mountains (Eisenhower tunnel and Raton pass included). Next time, I'll keep track of the Aerosaurs, Windstoppers and Freeloaders I breeze by as they're sucking wind in the Rockies. > Toyota, like many import brand engines are designed to > produce their HP at higher RPMs than the engines in domestic brands, that is > why they run out of tongue rather quickly at speed. Actually, you'll find that the 2005 Sienna 3.3L-V6 develops its greatest torque at a lower RPM than the Freestar's 3.9L-V6 does.* It just provides more maximum HP at higher revs because the torque doesn't fall off as fast at higher RPMs with the Toyota engine as it does with the Ford. I suppose the Toyota engine is designed more carefully and machined to closer tolerances, so it's not shaking itself to pieces at >5000rpm. > The reason is domestics > sell mostly automatic tyrannies in the majority of their vehicles that are [quoted text clipped - 12 lines] > > mike hunt * - Source: Edmunds.com. http://www.edmunds.com/new/2006/toyota/sienna/100604394/specs.html? tid=edmunds.n.researchlanding.leftsidenav..8.Toyota* http://www.edmunds.com/new/2006/ford/freestar/100542582/specs.html? tid=edmunds.n.researchlanding.leftsidenav..8.Ford* Oh, look, the Toyota develops more power than the bigger Freestar engine, too: http://www.edmunds.com/new/2006/ford/freestar/100542582/specs.html? tid=edmunds.n.researchlanding.leftsidenav..8.Ford* What else did Edmunds have to say about the Freestar? http://www.edmunds.com/new/2006/ford/freestar/100542582/ researchlanding.html "Unrefined powertrains with less horsepower and worse fuel economy than those of competing minivans, low-grade interior materials, hard-to-remove second-row seats..." By the numbers... Vehicle Curb Weight Power lb/hp MPG Sienna 4140lbs 215 19.3 Decent Freestar 4275lb 201 21.2 Sucky I was not specifically referring to any particular vehicle or brand but you just provided your own source that proves MY point, thanks. HP at the proper RPMs in relation to the torque is what is most important not HP alone. The Siena needs to be run all the way up to 5600 RPMs to develop its 215 HP far over its maximum torque of 222 FP at 3600 RPMs The Freestar develops its HP at well over 1000 RPMs lower at only 4250, much closer to its maximum torque of 263 FP at a RPM higher than the Sennia. Much better attuned at using the torque available in each example you cited, and the reason Toyotas are generally underpowered compared to its competitors vehicles whether you agree or not is immaterial. There are nay number of other domestic vehicles you could research and you will find the same high HP to tongue disparage mike hunt >> Not necessarily. It would depend at what RPMs each engine produced its >> maximum torque. It is after all tongue, not HP, that get the vehicle [quoted text clipped - 75 lines] > Sienna 4140lbs 215 19.3 Decent > Freestar 4275lb 201 21.2 Sucky > I was not specifically referring to any particular vehicle or brand but you > just provided your own source that proves MY point, thanks. HP at the > proper RPMs in relation to the torque is what is most important not HP > alone. The Siena needs to be run all the way up to 5600 RPMs to develop > its 215 HP far over its maximum torque of 222 FP at 3600 RPMs So? It still develops more power than the Freestar and the torque to do it comes on at lower RPMs. Ford would love to declare a higher HP number for the Freestar, no matter what the RPM, but their crappy engine's power output falls off dramatically above 4600RPM as it starts to shake itself apart. > The Freestar > develops its HP at well over 1000 RPMs lower at only 4250, much closer to > its maximum torque of 263 FP at a RPM higher than the Sennia. So the Toyota downshifts if necessary. Except that I haven't noticed that mine ever downshifts on the freeway, unless I really want to accelerate. It's not underpowered. If the Ford's maximum HP and maximum torque are, as you point out, close together, that describes an engine with a narrow power band - one that would require more frequent shifting. > Much better > attuned at using the torque available in each example you cited, and the > reason Toyotas are generally underpowered compared to its competitors > vehicles whether you agree or not is immaterial. There are nay number of > other domestic vehicles you could research and you will find the same high > HP to tongue disparage So you say, but you never bring out any facts and figures to support your allegations. Fact is, you're a blowhard. > mike hunt Don't think the Freestar's engine is junk? Don't take my word for it. Check with Edmunds: http://www.edmunds.com/new/2005/ford/freestar/100412870/researchlanding.html "Unrefined powertrains with less horsepower and worse fuel mileage than most competitors..." The fact is you are the blowhard. You supplied the facts yourself but you still don't understand the relative difference between HP and the ideal application of tongue to HP. I'll waste no more time trying to enlighten you on the subject.. Ford could easily develop more HP for that engine by winding it up if they chose to, but the torgue available at the normal driving rage of 2,000 RPMs makes for a better performing engine. If you are satisfied with the power your vehicle has that is your opinion and your business. The fact is those in the industry knows otherwise, Toyotas are generally underpowered vis a v their domestic comparators, whether you happen to agree or not. is immaterial. mike hunt >> I was not specifically referring to any particular vehicle or brand but > you [quoted text clipped - 42 lines] > most > competitors..." > The fact is you are the blowhard. You supplied the facts yourself but you > still don't understand the relative difference between HP and the ideal [quoted text clipped - 9 lines] > > mike hunt Ah, the unsupported "underpowered" assertion again. Can'te leave it alone, can you? But you can't supply any facts, either, can you? You're the bllowhard. The '05 Sienna has more power than the '05 Freestar. Remember what Edmunds had to say about the Freestar: http://www.edmunds.com/new/2005/ford/freestar/100412870/researchlanding.html "Unrefined powertrains with less horsepower and worse fuel mileage than most competitors..." The Camry is one of the most popular cars on the market. Toyota actually makes money selling them. Most people think the 4 is at least adequately powered or they wouldn't buy them and Toyota wouldn't make money selling them. Friends who drive them think they move out just fine (and none of these owns one of the latest with VVTi and a better power-to-weight ratio than ever before). Case closed. Of course, we're talking about normal sedans and other passenger cars, not fuel-wasting penis-substitutes such as the Mustang GT. If you really need your fuel-wasting penis-substitute, and consider anything less than a fuel-wasting penis-substitute to be underpowered, well. we can't help you there. Camry may still be the number one selling car but it was never the number one vehicle sold in the US. The F150 is the number one seller and has been for nearly thirty years, at just about twice as many sold as the Camry. Camry is aparently not as popular as it was last year either. Cold it be becse they are underpowered? The Camry was the ONLY vehicle in the top five to lose sales in 2005, it dropped around 20,000 sales, falling from third place to fourth below the Dodge Ram. The others all gained sales, including the Honda Accord, which is actully made in the US, not merely assembed of imported parts like the Camry VEHICLE Sales Y-T-D 2005 Last Yr. '04 Rank Chg. 1 Ford F-Series pickup 760,929 740,817 1 +2.7 2 Chevrolet Silverado pickup 616,139 575,886 2 +7.0 3 Dodge Ram pickup 409,252 362,122 6 +13.0 4 Toyota Camry 383,478 403,136 3 -4.9 5 Honda Accord 371,307 367,210 5 +1.1 "dh" <dh@stargate.com> wrote in message > > The Camry is one of the most popular cars on the market. Toyota actually > makes money selling them. Most people think the 4 is at least adequately > powered or they wouldn't buy them and Toyota wouldn't make money selling > them. Friends who drive them think they move out just fine (and none of > these owns one of the latest with VVTi and a better power-to-weight ratio > than ever before). > Camry may still be the number one selling car but it was never the number > one vehicle sold in the US. The F150 is the number one seller and has been [quoted text clipped - 13 lines] > 4 Toyota Camry 383,478 403,136 3 -4.9 > 5 Honda Accord 371,307 367,210 5 +1.1 Wow! I never realized that the top 3 selling vehicles in America are pick-up trucks. That's enlightening. Rich > Camry may still be the number one selling car but it was never the number > one vehicle sold in the US. The F150 is the number one seller and has been [quoted text clipped - 13 lines] > 4 Toyota Camry 383,478 403,136 3 -4.9 > 5 Honda Accord 371,307 367,210 5 +1.1 Having exactly what to do with your repeated unsupported allegation that Toyotas are underpowered? Still, with every pickup, you get highway mileage in the teens! Yippee! And, in spite of its voracious appetite for gas, Edmunds had this to say about the F150: http://www.edmunds.com/new/2005/ford/f150/100447759/researchlanding.html "Feels sluggish even with larger V8." Gee, thirsty AND slow. Who would have expected THAT from a Ford? Get some facts and a clue and get back to us. > "dh" <dh@stargate.com> wrote in message > > [quoted text clipped - 4 lines] > > these owns one of the latest with VVTi and a better power-to-weight ratio > > than ever before). > "Mike Hunter" <mikehunt2@mailcity.com> wrote in message >>VEHICLE Sales Y-T-D 2005 Last Yr. '04 Rank Chg. >> [quoted text clipped - 3 lines] >> 4 Toyota Camry 383,478 403,136 3 -4.9 >> 5 Honda Accord 371,307 367,210 5 +1.1 2006 is certain to take away a lot of the thunder from Mr. Hunter's argument. Large truck and SUV sales are dropping like a rock while sedan and small crossover SUV sales are increasing. Somewhere in the next couple of years Toyota is going to pass GM in worldwide sales volume and will never look back. If the Delphi bankructcy results in supply distruptions to GM, which is highly likely, then 2006 will be the year of the changing of leadership for sure. Years ago GM unseated Ford and has never looked back. GM did it with a better product range and agressive salesmanship. Unfortunately Detroit has had it's eye off the ball for too many years now. John How did you arrive at that conclusion? The ONLY vehicle in the top five to drop in sales was the Camry, all the others have gone up. Trucks and SUVs still account for half of all sales combined and there are a lot more car models than light truck models on the market. Perhaps you meant to say in my opinion? ;) mike hunt >> "Mike Hunter" <mikehunt2@mailcity.com> wrote in message > [quoted text clipped - 20 lines] > > John Part of the reason the 3 pickups (they are not trucks-a dumptruck is a truck, an 18-wheeler is a truck) made it to the top 3 is because Chrysler, Ford & GM used the lure of "employee discount" to pad the sales. Honda and Toyota used their normal discounts for this time of year. GM lost over a billion in the last quarter. Analysts say both GM and Ford will be out of business by 2015. The only sales they will get are the typical "must buy American" sheep. > How did you arrive at that conclusion? The ONLY vehicle in the top five > to drop in sales was the Camry, all the others have gone up. Trucks and [quoted text clipped - 28 lines] >> >> John Once again you are confused. The sales figures are for the F150 & F250, the Silverado and the Ram trucks for sizes up to 8,500 GVWR. IF all light trucks were include, the total figures would be even higher. Trucks over 8,500 like the F250HD and the F350 are not counted in the individual sales figures. Light trucks like the current leaders has nothing to do with discounts, light trucks have been outselling cars since 1975 when the majority of car went to FWD. The Ford F150 is by far the best selling vehicle had has been for nearly thirty years. When SUVs are included light truck sales have exceed car sales for several years. Perhaps you might want to do some research before commenting further on a subject of which you apparently have little or no knowledge, or at least say in my opinion. mike hunt > Part of the reason the 3 pickups (they are not trucks-a dumptruck is a > truck, an 18-wheeler is a truck) made it to the top 3 is because Chrysler, [quoted text clipped - 3 lines] > business by 2015. The only sales they will get are the typical "must buy > American" sheep. >> How did you arrive at that conclusion? The ONLY vehicle in the top five >> to drop in sales was the Camry, all the others have gone up. Trucks and [quoted text clipped - 13 lines] >>>>> 4 Toyota Camry 383,478 403,136 3 -4.9 >>>>> 5 Honda Accord 371,307 367,210 5 +1.1 > Once again you are confused. The sales figures are for the F150 & F250, the > Silverado and the Ram trucks for sizes up to 8,500 GVWR. IF all light [quoted text clipped - 12 lines] > > mike hunt Why? Do you qualify YOUR lame, unsubstantiated opinions with "in my opinion?" > > Part of the reason the 3 pickups (they are not trucks-a dumptruck is a > > truck, an 18-wheeler is a truck) made it to the top 3 is because Chrysler, [quoted text clipped - 21 lines] > >>>>> 4 Toyota Camry 383,478 403,136 3 -4.9 > >>>>> 5 Honda Accord 371,307 367,210 5 +1.1 So the top two passenger cars are Toyota and Honda? Conclusion: people like them more than they like Fords, Chevys and Pontiacs. Maybe they think they're a better value. Maybe they hate wasting money on gas and would rather get a car that gets good gas mileage than one that gets mediocre gas mileage. Gee... Maybe Detroit should think about that. By the way, I notice you didn't provide a reference. We're supposed to believe your figures? >>Once again you are confused. The sales figures are for the F150 & F250, > [quoted text clipped - 85 lines] > By the way, I notice you didn't provide a reference. We're supposed to > believe your figures? Synergy beats Honda. Again you are confused I don't present opinions, what I posted are fact that are available to anybody willing to do the search. Although Toyota and Honda have the number one and two selling individual model cars, and Ford has the best selling individual truck GM sell more cars than Ford, Toyota and Honda as well as more trucks than Ford, Toyota and Honda . As to fuel mileage GM offers far more vehicles that get over 30 MPG than does Toyota. GM even offers a full sized V8 Chevrolet that gets nearly 30 MPG. Better do some research if you are going to continue to post on this subject mike hunt . >> Why? Do you qualify YOUR lame, unsubstantiated opinions with "in my >> opinion?" [quoted text clipped - 57 lines] >> > Synergy beats Honda. > Again you are confused I don't present opinions, Yes, you are offering opinions. Lame, unsubstantiated opinions. > what I posted are fact that > are available to anybody willing to do the search. Then it should be very easy for you to provide references and sources. Others do so. > Although Toyota and > Honda have the number one and two selling individual model cars, and Ford > has the best selling individual truck GM sell more cars than Ford, Toyota > and Honda as well as more trucks than Ford, Toyota and Honda . As to fuel > mileage GM offers far more vehicles that get over 30 MPG than does Toyota. If this is so, it should be very easy for you to name these vehicles. The Cobalt comes to mind. Any others? > GM even offers a full sized V8 Chevrolet that gets nearly 30 MPG. If it exists and you know if it, it should be trivially easy for you to name it. Do so. > Better > do some research if you are going to continue to post on this subject Yes, you'd better do some research. Surprise us with a fact or two. > mike hunt > [quoted text clipped - 48 lines] > >> > > Synergy beats Honda. I've noticed that with the same "small" car Toyotas seem to get about 20% better gas mileage. The Corolla gets 40mpg and Chevy Cobalt, which has a bigger engine but the same power output gets about 20% less. Why is that? Is GM just that far behind technology wise? Is that why their stock price is at 20 year lows and they lose money every quarter? >I've noticed that with the same "small" car Toyotas seem to get about >20% better gas mileage. [quoted text clipped - 4 lines] >Why is that? Is GM just that far behind technology wise? Is that why >their stock price is at 20 year lows and they lose money every quarter? Tuning. American cars/engines are tuned to bias their torque lower down the rev range. Makes it more compatable with the ubiquitus slush-box americans love. Result is the calculated peak power is the same, although its a bigger engine, ANd a more inefficient engine results. I don't do homework for my own grandchildren what make you think I would do yours? Research the EPA fuel economy guide for the facts on fuel mileage. Search the bible of the auto industry, automtivenews.com, for sales figures. mike >> Again you are confused I don't present opinions, > [quoted text clipped - 92 lines] >> >> >> > Synergy beats Honda. > I don't do homework for my own grandchildren what make you think I would do > yours? Research the EPA fuel economy guide for the facts on fuel mileage. > Search the bible of the auto industry, automtivenews.com, for sales figures. > > mike This isn't OUR homework, this is YOUR homework. Got facts for your lame opinions? Then post them. I've taken the time to provide comparisons. Don't like my comparisons? Refute them with facts of your own. > >> Again you are confused I don't present opinions, > > [quoted text clipped - 92 lines] > >> >> > >> > Synergy beats Honda. Why don't you f.ck off back to your Ford ng? > How did you arrive at that conclusion? The ONLY vehicle in the top five > to drop in sales was the Camry, all the others have gone up. Trucks and [quoted text clipped - 28 lines] >> >> John That's funny. Some guys in the Ford NG tell me to go back to the GM NG when I point out GM outsells Ford. Some guys Honda NG tell me to go back to the Toyota NG when I point out Toyota outsells Honda They don't like to be presented with facts that disputes their personal biases and opinions either it seems ;) mike hunt > Why don't you f.ck off back to your Ford ng? > [quoted text clipped - 30 lines] >>> >>> John > That's funny. Some guys in the Ford NG tell me to go back to the GM NG when > I point out GM outsells Ford. Some guys Honda NG tell me to go back to the [quoted text clipped - 3 lines] > > mike hunt Ya know, if just one guy tells you to go away, maybe it's just him and his reaction to you. If everybody's telling you to go away... ya might just get a clue... Well, you wouldn't. > > Why don't you f.ck off back to your Ford ng? Your bias is showing, again. ;) mike >> That's funny. Some guys in the Ford NG tell me to go back to the GM NG > when [quoted text clipped - 15 lines] > >> > Why don't you f.ck off back to your Ford ng? >>Camry may still be the number one selling car but it was never the number >>one vehicle sold in the US. The F150 is the number one seller and has [quoted text clipped - 53 lines] > >>>than ever before). Yea. Gotta love those offset crash test videos! Total it, and if you survive, buy another! > Not necessarily. It would depend at what RPMs each engine produced its > maximum torque. It is after all tongue, not HP, that get the vehicle going [quoted text clipped - 11 lines] > tranny the gear selector can be used to stay on the tongue curve to climb > grades, particularly long grades. <snip> Power is the ability to accomplish work from a physics point of view and it is indeed power which is required to overcome wind resistance, move a certain distance and/or increase potential energy (climb a hill). There is great misunderstanding about the relationship between torque and power. In modern times the distinctions between manual and automatic transmissions are becoming moot in this regard as today's automatic transmissions often have five or six forward gears, which gives them even more flexibility for optimizing the relationship between engine speed (RPMs) and work being done than ever before. I don't think that you actually understand the function of a torque converter either. It is essentially and infinitely variable transmission which goes between the engine and the main transmission and provides for a range of ratios between the two. Modern ones also include an electrically activated lockiing clutch to disable the converter under cruise conditions and thus get rid of the high amount of power loss in the little buggers. In modern times the differences between "import" and "domestic" motor design points is becomming smaller all the time. Cadillac's Northstar has far more in common with a Lexus V-6 than it does with a traditional 1960s style GM motor. The current GM Ecotec 4 cyclinder motor is very similar to similar size Japanese and European designs. In fact, GM puts a turbo version of it in the Saabs. Your Japanese/Domestic comparisons are off the mark and meaningless. I will gladly take on any V-6 equipped modern Chevrolet or Ford at the local drag strip or road racing course with my V-6 Honda Accord. GM is only now starting to implement variable valve timing used to flatten the torque curve as Honda has been doing for years. John You are entitled to you own opinion but the proof is in the pudding, as they say. You can prove it too yourself if you wish. Drive in hilly or mountainous parts of the county and notice which vehicles fall behind others when you come to a grade. ;( mike hunt >> Not necessarily. It would depend at what RPMs each engine produced its >> maximum torque. It is after all tongue, not HP, that get the vehicle [quoted text clipped - 46 lines] > > John > You are entitled to you own opinion but the proof is in the pudding, as they > say. You can prove it too yourself if you wish. Drive in hilly or > mountainous parts of the county and notice which vehicles fall behind others > when you come to a grade. ;( > > mike hunt I drive through the Sierra Nevadas frequently and the Rocky Mountains once every few years. Our V-6 Honda is much, much better at this than is our V-6 Oldsmobile. John >> You are entitled to you own opinion but the proof is in the pudding, as they >> say. You can prove it too yourself if you wish. Drive in hilly or [quoted text clipped - 8 lines] > > John Please don't feed the trolls. > Please don't feed the trolls. In general, I'd AOL that. In this case, Mike Hunter doesn't even make it to "troll" status, just "loud-mouthed ignoramus". And we seem to be creating an interesting discussion despite him. <g> SignatureAndrew Stephenson I own a pickup and a minivan, and I notice that pickups always fall behind on grades because of their poor wind resistance. It is why hybrid technology is wasted on pickups and SUVs for MPG and why huge engines are wasted on them also. You can push a billboard through the wind only so fast. It seems like the fastest drivers on highways have Accords and Jettas. > You are entitled to you own opinion but the proof is in the pudding, as > they say. You can prove it too yourself if you wish. Drive in hilly or [quoted text clipped - 53 lines] >> >> John What's the relationship between torque and HP? I never understood that. And I had a year of physics at an engineering shchool. I know power is work and torque is twisting force (F * r), but somehow I would think the two would be very similar. > What's the relationship between torque and HP? I never understood > that. [quoted text clipped - 3 lines] > I know power is work and torque is twisting force (F * r), but somehow > I would think the two would be very similar. The difference is in the rpm curves. It really all hinges on the torque anyway, as you point out, since for a given torque the hp rises in proportion to rpm. The low end torque is stuff I never really got a handle on, but at the high end (where most of the controversy is anyway) it is all related to breathing. Things like intake and exhaust design and cam considerations of valve lift, duration and overlap can increase the useful torque at high rpms and thereby increase the maximum power. The torque/power debate really comes down to gearing. If we could select any gear ratio we wanted any time we wanted, we could make good use of maximum power and nobody would talk about torque. Back in the real world, within each gear ratio, the torque curve determines the acceleration we feel. Mike >> What's the relationship between torque and HP? I never understood >> that. [quoted text clipped - 17 lines] >gear ratio we wanted any time we wanted, we could make good use of maximum >power and nobody would talk about torque. Such as, ohhh, with a CVT? Had a few of them over the years, kinda weird sitting there, accelerating, and getting NO change in the engine note, as it holds at its peak torque point, Good old rubber band cars, much more efficient than regular slushboxes too, since they dont have so many nasty planetaries. > Back in the real world, within >each gear ratio, the torque curve determines the acceleration we feel. > >Mike > Such as, ohhh, with a CVT? Had a few of them over the years, kinda > weird sitting there, accelerating, and getting NO change in the engine > note, as it holds at its peak torque point, Good old rubber band cars, > much more efficient than regular slushboxes too, since they dont have > so many nasty planetaries. In full throttle situations the CVT should be tunned to hold the engine at the peak power output point, not the peak torque point. John >>> What's the relationship between torque and HP? I never understood >>> that. [quoted text clipped - 26 lines] > much more efficient than regular slushboxes too, since they dont have > so many nasty planetaries. Of course, the Toyota hybrid system has a variation without the rubber band. Nothing shifts, nothing engages or disengages. The engine doesn't even exclusively provide torque to the wheels, but provides power to the hybrid system. Mike > What's the relationship between torque and HP? I never understood > that. [quoted text clipped - 3 lines] > I know power is work and torque is twisting force (F * r), but somehow > I would think the two would be very similar. http://www.geocities.com/CapeCanaveral/Lab/8679/motor.html > > What's the relationship between torque and HP? I never understood > > that. [quoted text clipped - 5 lines] > > http://www.geocities.com/CapeCanaveral/Lab/8679/motor.html wow that page is from 1997 too > What's the relationship between torque and HP? I never understood > that. > > And I had a year of physics at an engineering shchool. Re-read the chapters of the text on work, power, and torque. > I know power is work No. Power is work delivered per unit time. > and torque is twisting force > (F * r), but somehow > I would think the two would be very similar. Google for explanations that will probably be better than any given off the top of one's head here or at any personal web site. http://www.straightdope.com/mailbag/mhorsepower.html isn't bad. -- Honda home studies: http://home.earthlink.net/~honda.lioness -- Thanks for that straightdope line. I knew power was work/time, just misspoke. That's the best explanation I've heard. Considering the same vehicle weight and gearing, the vehicle with the higher HP will go faster. Considering the same vehicle weight and HP the vehicle that develops its torque at lower RPMs will be more powerful. Torque is what enables a vehicle to get going from a stop more quickly and keeps it going under load. mike hunt > Thanks for that straightdope line. I knew power was work/time, just > misspoke. > > That's the best explanation I've heard. > What's the relationship between torque and HP? I never > understood that. [...] At the risk of repeating what others and have said and what you know already... Torque is, basically, a rotational (ie, twisting) force. HP (horsepower) is a rate of doing work, so can also be expressed in units such as watts (the modern preference, 1 HP == 746 watts) and BTU (if one must). An easy way to remember the equivalence between Force, Distance (over which the Force is used) and Work (another way of saying Energy) is to recall that Work = Force * Distance So Power, the Rate Of Doing Work, is Work / Time Therefore the Work done by Torque is, in effect, the Force acting at a certain Leverage distance, tracing a circular path around a point, over a certain Time. One final relationship: Torque = Force * Leverage where Leverage is the distance between the line-of-action of the Force and the pivot point, about which the Torque is calculated. A 15 kilo Force pushing on a lever 2 metres long exerts a Torque at the pivot point of 15*2 kilo-force-metres (not to be confused with kilometres). Most engineers use Newtons, not kilos-force: Newton = Kilo * 9.81 (approx) So that Torque would actually be (about) 294.3 Newton-metres. Back to the original question... Work done in 1 revolution = 2 * pi * Leverage * Force = 2 * pi * Torque So rate of doing work (ie, Power) = 2 * pi * Torque / Time_for_1_rev = 2 * pi * Torque * Revs_per_second = watts Use Newton-metres here and it is a doddle to compute Power. If you absolutely must know the HP, divide Watts by 746. (FWIW, AFAIK: 1 Pound-force-foot == 1.355818 Newton-metres. And for pi you can get by with 3.14159, though it goes on to many <g> more significant digits than that.) Grief, I hope I got that lot right. <g> If anyone knows better, do let me know soon. SignatureAndrew Stephenson Thank you very much for your informative reply. > What's the relationship between torque and HP? I never understood > that. [quoted text clipped - 3 lines] > I know power is work and torque is twisting force (F * r), but somehow > I would think the two would be very similar. Torque X rotational speed = Power. To get the units right in various systems, a conversion factor is used. A very good discussion is available on the web at: http://www.straightdope.com/mailbag/mhorsepower.html Power is the ability to do work. Work is needed to move a mass from one place to another, to increase elevation, to increase velocity (acceleration) and to overcome frictional losses like air resistance, tire rolling resitance, etc. Thus, for example, 200 ft. lbs. of torque at 4,000 RPM can accomplish twice as much work as can 200 ft. lbs. of torque at 2,000 RPM. Put another way, 400 ft. lbs. at 1,000 RPM can do the same work as does 200 ft. lbs at 2,000 RPM. For the units used in the US: Power (HP) = [Engine Speed (RPM) x Engine Torque (ft.lbs.)] / 5252 It is really that simple. John hybrids don't just work by capturing braking energy. They run a more fuel efficient cycle with a longer expansion stroke. The Miller/Atkinson cycle. They can do this because acceleration is supplemented by the battery. They also have a smaller engine b/c it can use batteries to accelerate. By using the Miller cycle they get a higher % of energy out of the gas and into the drivetrain. It's very ingenious. Hydrogen is probably never going to "be here". You need a fuel source to get hydrogen. Hydrogen is very hard to transport (harder than natural gas which is difficult enough) and there are no cheap "fuel cells". The advantages of a liquid fuel are great. I think the next step is using a smaller gas engine and a larger/cheaper battery that you can plug in. You could plug it in for an hour a night and that would take you maybe 30-40 miles. On longer trips and under acceleration the gas engine would turn on. That way you'd be replacing gas with electricity, which can come from nuclear/coal/wind whatever. > Hydrogen is probably never going to "be here". You need a fuel source > to get hydrogen. How do you figure? You need a power source, not a fuel souce. The power is electrical. It can be generated from wind power and solar power. The current hydrogen research being subsidized by the Bush administration is indeed planning on the oil industry being the primary source of this "fuel" you mention. Otherwise they wouldn't be subsidizing it. That's one of the main reasons hydrogen has been put on the back burner for 30 years. Anyone with a windmill, the production equipment, and a storage tank can produce hydrogen. No profit there. > Hydrogen is very hard to transport (harder than > natural gas which is difficult enough) and there are no cheap "fuel > cells". Hydrogen can be pressurized and stored just like propane. It is no more dangerous than gasoline. In fact, in some ways it's safer. After gasoline's initial explosion, the liquid gas remains and burns furiously. Once hydrogen explodes, that's it. It's all gone. Fuel cells are unnecessary. Hydrogen will burn in reciprocating combustion engines just like other flammable gas (natural, propane). All this was known 30 years ago. The boogie-man scare tactics and disinformation are all oil industry bullshit. nb Hydrogen is less dense than propane or natural and takes alot more energy to pressurize it (and higher pressures). Because of the higher pressures, hydrogen tanks on a car would have to have very heavy and thick steel. As for burning hydrogen in a car, it would be negate the benefits of hydrogen. The point of a fuel cell is the high efficiency. Burning it in an engine would negate that. You could make a case for combining hydrogen with coal to make diesel fuel. The ease of transport alone would make it worthwhile. A gallon of gas has about 36 kwh of heat energy. Generating that much heat energy from wind would cost about $2.00 at a minimum. Converting it to hydrogen at 50% efficiency would make it $4 a gallon equivalent. And that's not counting the capital equipment to make the conversion. Then you have the pressurization and transport losses. Oil companies have no fear of "hydrogen". If anything they would encourage the gov't to fund it. It's pie in the sky. What they would fear is coal to oil technologies and conservation. > A gallon of gas has about 36 kwh of heat energy. Generating that much > heat energy from wind would cost about $2.00 at a minimum. Wind is free. So is sunlight. Granted, at this stage these technologies are still in their infancy, but there's a reason for that. Hard to promote/fund a technology the developers can't monopolize for their own gain. This also for storage. Alloys and synthetics have replaced steel in storage containers. Hydrogen tanker trucks ply our freeways daily with no cavalcade of security/safety vehicles. It's all bunk. So what if efficiency is less? Early gas engines were inefficient, too. It's the pollution that's important. Four decades ago a four function calculator cost $600. Today they're in a kid's wristwatch you get free in a box of breakfast cereal. This kind of technological advancement could have been applied to hydrogen technology and we'd all be driving hydrogen cars today. But, there's no incentive in exploring it and it has advanced little. You are throwing up the same arguments the naysayers did 30 years ago. This doesn't mean these problems are not solvable, it means no one has done a damn thing in 30 years. nb >> A gallon of gas has about 36 kwh of heat energy. Generating that much >> heat energy from wind would cost about $2.00 at a minimum. [quoted text clipped - 3 lines] > that. Hard to promote/fund a technology the developers can't > monopolize for their own gain. Oil is also free. It is the harvesting of these things that costs money. Wind turbines are still fairly expensive to buy and maintain, and the land is rarely free. The electric company I work for has an 86 KW solar site on a couple million dollars worth of land... go figure. > This also for storage. Alloys and synthetics have replaced steel in > storage containers. Hydrogen tanker trucks ply our freeways daily > with no cavalcade of security/safety vehicles. It's all bunk. So > what if efficiency is less? Early gas engines were inefficient, too. > It's the pollution that's important. The storage problems may be solvable, but not yet. At a recent alternative energy fair I saw a 3/4 ton pickup with 150 mile range, courtesy of the three large hydrogen tanks that overfilled the bed. > Four decades ago a four function calculator cost $600. Today they're > in a kid's wristwatch you get free in a box of breakfast cereal. This [quoted text clipped - 4 lines] > doesn't mean these prob |
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