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Car Forum / Driving, Maintenance, Tuning / RVs / July 2006What is "normal" for pulling a TT?
I know my subject is kind of cryptic, and I apologize. Let me give some more background: I have a 2001 Chevy Silverado Ext Cab with the 5.3L V8. I used to tow a 12' pop-up, and we recently moved up to a 23' hybrid (Jayco 23B). To prepare, I added a tranny cooler, changed the rear diff and coolant, and switched to synthetic oil. I guess I was spoiled when I towed the pop-up. Cruising on the highway at 75mph was no problem. Towing the TT is of course a whole different story. It's UVW is right about 4000 pounds, and we specifically went with that to make it lighter and easier to tow. I've towed it about three times, and I was wondering how much of the time I should spend in 3rd gear? How often does the cooling fan run (HOT here in Texas)? What is the recommended towing speed? What mpg should I expect? Sorry for the questions - I'm kind of anal retentive about my truck. Although I'm sure everything is perfectly normal, I just don't know what to expect. Thanks for sharing your experiences. > I've towed it about three times, and I was wondering how much of the > time I should spend in 3rd gear? How often does the cooling fan run > (HOT here in Texas)? What is the recommended towing speed? What mpg > should I expect? With your 4L60E transmission always tow in 3rd gear. OD in that transmission is weak. Also, the frontal area of the new trailer will cause you to use more fuel so to get the best MPG slow down. Glenn Water is the best coolant in an automotive cooling system (btu/lb) , so, use 25% actual Coolant to 75% distilled water . Add a bottle of Redlines Water Wetter also. You will see a big difference in the Temp. Also, take a look around the sides of the a/c's condensor and radiator...and seal up any gaps so no air is short-circuited from the sides by the fan. Make sure your fan shroud is also sealed up tight so you pull maximum air thru the condensor and radiator. Of course , clean out your Cooling System real good with Prestone Cleaner and Flush method using their flushing Tee and open all block drains when draining/flushing out. Lastly, make sure your lower radiator hose is not mushy as it could start to collapse at higher rpms and really increase your Cooling System temps. Good luck and happy trails. >Water is the best coolant in an automotive cooling system (btu/lb) , so, >use 25% actual Coolant to 75% distilled water This is REALY bad advice! THere is so much misunderstanding here and I am not sure who started it all. Glycol weighs more than water (it is denser) and it takes more BTU to heat a gallon of antifreeze than a gallon of water. It does take more BTUS to boild of water than glycol but you do not want to boil it of in your cooling system. Also in your modern mixed alloy engine galvantic corrosion is a big potenail problem and the above advice opens the door wide open to this because water is VERY reactive in a engine block of aluminum and cast iron parts and the more water used the worse it is. ALso, the reason that water appears to run coolier some times is because in a hot motor a bubble barrier will form between hot metal and coolant insulating the parts for water/coolant and allowing them to get hotter and since temp gage reads coolant temp amd not block temp you think it is cooler. Ethylene Glycol has a much lower surface tenson which is the abilty to form and hold bubles that insulate block heat from being removed and it also has a much higher boiling point too (pure antifreeze boils at about 340 degrees) so there is much better heat transfer to coolant. (which may appear warmer at times because it is getting the heat out) I have run 70% antifreeze for many years and I even run a lower pressure cap to extend cooling system life on all my vehicle and I have no cooling problems ever and I have been through nebraska and soutern CO when it was close to 110 out with full A/C and NEVER even got above 210 nor ever lost coolant. Several trip up pikes peak too. Some read a few articles or adsl and take them for the gosphel and never check the science. ALso I have a old JD tractor (52 years old) that I still use bush hoging in summer heat and it can be 90 plus and I will lose my cool before it does (if never has in the 21 years I have had it) and it has only a 4 PSI cap and about 90% antifreeze (because I cannot risk corrosion in such a old peiece of equipment that parts are scarce for (unlike some the restore tractors for show I use them too) and the coolant is still clean as can be. One more thing there is basically two type of glycol based antifreezes., Eythlene Glycol (most common) whcich reaches max frezer protection at about 70% and max boil at 100% and Proplene Glycol (also called non toxic) which reachs max frezing and boiling point at 100% and is used in most artic ablications requiring goolant. DO NOT run lower than 50/50 in your new truck as your risk galvantic problems (60/40 or more is better here). ALso, if you have triouble cooling engine, you might check operation of engine cooling fan because as they ship, their timing for engagment is for low noise and a fraction more MPG, not for best cooling. If all else fails, you need a bigger raditor as factory ones again are not generous in some models. There is no magic snake oil to fix this proiper ----------------- The SnoMan www.thesnoman.com "Water is the best coolant in an automotive cooling system (btu/lb) , so, use 25% actual Coolant to 75% distilled water" This is REALY bad advice! THere is so much misunderstanding here and I am not sure who started it all. Glycol weighs more than water (it is denser) and it takes more BTU to heat a gallon of antifreeze than a gallon of water. It does take more BTUS to boild of water than glycol but you do not want to boil it of in your cooling system. Also in your modern mixed alloy engine galvantic corrosion is a big potenail problem and the above advice opens the door wide open to this because water is VERY reactive in a engine block of aluminum and cast iron parts and the more water used the worse it is. REPLY: Thats why i suggested a bottle of Water Wetter solution because it has all the corrosive inhibitors you need for your cooling system. 'ALso, the reason that water appears to run coolier some times is because in a hot motor a bubble barrier will form between hot metal and coolant insulating the parts for water/coolant and allowing them to get hotter and since temp gage reads coolant temp amd not block temp you think it is cooler. Ethylene Glycol has a much lower surface tenson which is the abilty to form and hold bubles that insulate block heat from being removed and it also has a much higher boiling point too (pure antifreeze boils at about 340 degrees) so there is much better heat transfer to coolant. (which may appear warmer at times because it is getting the heat out)' REPLY: Why do u think Indy Race Car Drivers run straight water then ? 'Some read a few articles or adsl and take them for the gosphel and never check the science.' REPLY: You mean : Gospel. 'DO NOT run lower than 50/50 in your new truck as your risk galvantic problems (60/40 or more is better here)' REPLY: Bad advice ! To to www.redline.com and read the technical articles from a Manufacturer who has a huge RandD Dept. and who knows the truth about this issue. REPLY: Why do u think Indy Race Car Drivers run straight water then ? Indy cars run on Alcohol (or methanol) which runs quite a bit cooler than gasoline or diesel.  SignatureJerryD(upstateNY) 'Why do u think Indy Race Car Drivers run straight water then ? Indy cars run on Alcohol (or methanol) which runs quite a bit cooler than gasoline or diesel. SignatureJerryD(upstateNY)' REPLY: You didnt answer the question though --- Why do they use straight water in the Cooling System ? And Dave claims to be in HVAC. > >Water is the best coolant in an automotive cooling system (btu/lb) , so, > >use 25% actual Coolant to 75% distilled water [quoted text clipped - 47 lines] > The SnoMan > www.thesnoman.com Dave's a pervert, too. 'And Dave claims to be in HVAC. ' REPLY: I certainly am. Been in the trade since 1974 . Before you spout off...try doing some research on the topic im discussing with SnoMan and you wont sound so presumptious and look stupid. Read : Address:http://www.redlineoil.com/products_coolant.asp?productID=53 >> 'And Dave claims to be in HVAC. ' >> >> REPLY: I certainly am. Been in the trade since 1974 . ...And he got away with several faulty installations too; didn't you HVAC hackman? Before you >> spout off...try doing some research on the topic im discussing with >> SnoMan and you wont sound so presumptious and look stupid. Do you not realise that you have the monopoly on that then? >> Read : >> Address:http://www.redlineoil.com/products_coolant.asp?productID=53 This excuse for a person pisses off everyone everywhere. : He just likes to lure people into his boring mindless senseless discussions about sweet FA; the sum of the combined intelligence in both of his braincells. Do yourselves a favour and ignore him. Signature"Christians, like slaves and soldiers, ask no questions." 1981 >> I've towed it about three times, and I was wondering how much of the >> time I should spend in 3rd gear? How often does the cooling fan run [quoted text clipped - 5 lines] > will cause you to use more fuel so to get the best MPG slow down. > Glenn Good advice, Glenn, and slowing down will, also, reduce the wear on the transmission and differential significantly, not to mention helping to let both the engine and transmission stay cooler. Lots of folks fail to appreciate the amount of wind resistance supplied by a TT - it's much higher than a pop-up but much less than a fifth-wheel - and the amount of damage that the added strain can (and will) cause on the entire drivetrain. >With your 4L60E transmission always tow in 3rd gear. OD in that >transmission is weak. Also, the frontal area of the new trailer >will cause you to use more fuel so to get the best MPG slow down. >Glenn This is good advise but it is not because the 4L60 has a weak OD by design as it does not, it is because it has a OD ratio of .7 which is pretty tall (vs .75 for 4L80) and it is usally coupled with a 3.42 or sometimes a 3.73 which makes a a really tall final ratio in OD that is placing a lot of strain on tranny even keeping speed ( it requiwith a ooad. If you are fourtune enough to have a 4.10 axle ratio with stock tires then you can safely use OD sometime during easier pulls but otherwise stay out of it towing. When you do the math, the engine has to make to make about 43% more torque (and tranny clutch have to hold it too) in OD to deliver same output torque before interanl lasses are figured in with a .70 OD. (at first thought you think it should be 30% but it is not because if you are in drive and you have a 100 ft lbs in and out (not counting internal losses0, when you shift into OD the engine has to input 143 ftlbs of torque to make the same 100 ft lbs on output shaft. (143 x .7 equal 100) so you can se how much you can load tranny especaily with taller gears. ----------------- The SnoMan www.thesnoman.com >>With your 4L60E transmission always tow in 3rd gear. OD in that >>transmission is weak. Also, the frontal area of the new trailer [quoted text clipped - 20 lines] > The SnoMan > www.thesnoman.com This is exactly the reason I have a Dodge Ram Heavy Duty 3500 Dually Long Bed with a 600 Cummins Turbo Diesel. I donut have to write a paragraph justifying my piece o crap toy truck to do a real trucks job. Under power/over weight/over speed with get your a.s killed. That is all. SignatureMoParMaN---Remove Clothes To Reply! --SCUD Coordinates 32.61204 North: 96.92993 West-- >This is exactly the reason I have a Dodge Ram Heavy Duty 3500 Dually Long >Bed with a 600 Cummins Turbo Diesel. I donut have to write a paragraph >justifying my piece o crap toy truck to do a real trucks job. Under >power/over weight/over speed with get your a.s killed. It is all in the gearing of the engine to the load. With a 4.56 behind a good gas motor you can move some killer load effectively. It simply needs a differnet final drive ratio to match a gas engine power curve to load which detriot does not provide in most models to make diesel look better. Back in the later 70's I drove a C70 triaxle Chevy dump truck for a while with a 427 and a 20 speed (5 x 4) and it had no problems moving 30 tons GVW around (were it was legal at weight wise) and another 5 ton with a specail permit or about a 25 ton payload when hauling blacktop for big paving contracts. You modern Cummins or Dmax P/U would bust its nuts moving trying that weight which I could move through any terrain that could support the truck including soft grond that REALLY sucks the power down at 30 tons. I alos drove a C60 with a 366 and a 10 speed (5x2) and hauld a float with a backhoe or a dozer on it from time to time and that little gas motor did a credible job and never had trouble starting a load out. Durring that same time frame I knew a farmer that used to haul his grain from his silo to mill or a cincinati port 80 miles away with a 75 Chevy dually std cab with a 454, 4.10 gears and a SM465 granny gear tranny. His GCVW was around 30k and it did a fine job with it and did it for many years too. Yes there are oil burner P/U can pull but so can a gasser if properly geared. A lot of the diesel advantage is exagerated by the fact that most gas trucks today are poorly geared for their tow ratings. If you had say a 8.1 checy dualie with say a 4.56 and a 6 speed ally with double OD it would pull ANYTHING that a stock Dmax or Cummins would an with less fuss most of the time too and be a lot more fun to drive too. I recently went with a friend who owns a 05 Dmax cc and we drove a o6 CC with a new Dmax and one with a 8.1 and the 8.1 would run circles around the Dmax and was gone while the Dmax was still trying to build boost. He was very impressed over the responce difference compared to his Dmax and is considering getting one while there is still time. ----------------- The SnoMan www.thesnoman.com >>which detroit does not provide in most models to make diesel look >>better.<< And where did you get this piece of (phony) information ? The U.S. government demanding more MPG out of every car/truck is the reason for having the tall gear ratios we have today. SignatureJerryD(upstateNY) > >This is exactly the reason I have a Dodge Ram Heavy Duty 3500 Dually Long > >Bed with a 600 Cummins Turbo Diesel. I donut have to write a paragraph [quoted text clipped - 13 lines] > through any terrain that could support the truck including soft grond > that REALLY sucks the power down at 30 tons. ok this is fair comparing a 1 ton p/u to a triaxle dump truck. heck if we're comparing stuff like that then lets compare a festiva to a peterbuilt. I alos drove a C60 with a > 366 and a 10 speed (5x2) and hauld a float with a backhoe or a dozer > on it from time to time and that little gas motor did a credible job [quoted text clipped - 15 lines] > difference compared to his Dmax and is considering getting one while > there is still time. let me know how he likes the fuel bill when he figures that part out. > ----------------- > The SnoMan > www.thesnoman.com Signature-Chris 05 CTD 06 Liberty CRD Real trucks don't need spark plugs >ok this is fair comparing a 1 ton p/u to a triaxle dump truck. heck if we're >comparing stuff like that then lets compare a festiva to a peterbuilt. I am comparing a engine that is PROPERLY geared to the load not the vehicle. I am tired of people saying you need a diesel to move anything when all you need is proper gearing to do it and if you have it you can easily move a lot a weight with a gas motor. Heck if GM offered a 4.56 with a 6.0 and new 6sp ally (which you can get in a Chevy on specail order starting in 06) it would surprize you what that engine would pull effectively. The ally has a 3.1 first gear vs 2.48 in 4L80 and a reverse more than twice as deep too which give the Dmax a even bigger percived edge over a 6.0 with a 4.10 and a 4L80. They both make about the same horse power it is just that one is properly geared to load from factory and one is not. A 8.1 with a 4.56 and a 6 speed would be a incredable tow beast. ANd if you through in a mild 6 or 7 PSI boost with a super (about 1 third of Dmax's boost) it would get a bit "scary" at times bebeing able to make about 700 ft lbs of torque from about 1500 RPM to past 4000 RPM rather than a bit more torque on a boosted deisel over a much narrower RPM range. (not to mention that 700 FT lbs out of a 8.1 is not going to hurt tranny much (it is rated at 650 ft lbs) but 800 to 900 ft lbs out of a booste Dmax will shorten trannies life. I can drag a truck out of a mud hole with old 30 HP JD tractor that a Dmax truck would not be able to do in same conditons. It is all in the proper gearing for load and engine, not the engines type. ----------------- The SnoMan www.thesnoman.com >>ok this is fair comparing a 1 ton p/u to a triaxle dump truck. heck if >>we're [quoted text clipped - 24 lines] > ----------------- > The SnoMan Yea, but the Dmax will get much better mileage and have a lot better ride than the 30 hp JD! You will also get to your destination before the end of the summer with the Dmax. <g> Ron >>>ok this is fair comparing a 1 ton p/u to a triaxle dump truck. heck if >>>we're [quoted text clipped - 30 lines] > > Ron That's right . . . you can also move a freight train with a 10Hp lawnmower engine if you can get it geared down enough just don't get in a race with a snail while doing it. SignatureNahmie The only road to success is always under construction. > I am comparing a engine that is PROPERLY geared to the load not the > vehicle. Your comparison has no merit when the question is about a pickup pulling a load, not about a tri-axle. > I am tired of people saying you need a diesel to move > anything when all you need is proper gearing to do it and if you have > it you can easily move a lot a weight with a gas motor. You can be tired all you like, but the facts are not in your favor. While true that you can move anything with a Briggs and Stratton if the gearing is correct, certain things make doing work easier. One of those is a diesel engine. A diesel has MANY benefits in doing work when compared to a gasoline engine. One of those is moving a heavy load at highway speeds without need for huge amounts of gearing and prohibitively large transmissions. > Heck if GM > offered a 4.56 with a 6.0 and new 6sp ally (which you can get in a > Chevy on specail order starting in 06) it would surprize you what that > engine would pull effectively. No, it would not surprise me. However, it might surprise YOU how much MORE fuel you burn and how much SLOWER a speed you go to do the work when compared with a diesel engine. > The ally has a 3.1 first gear vs 2.48 > in 4L80 and a reverse more than twice as deep too which give the Dmax > a even bigger percived edge over a 6.0 with a 4.10 and a 4L80. Why are we discussing the DMax? Its a POS engine to begine with. In your resistance to modern innovation, you ought to know a V8 isn't as efficient at pulling as an inline six like the Cummins. > They > both make about the same horse power it is just that one is properly > geared to load from factory and one is not. I am sure (AGAIN, after all these years) that the engineers geared BOTH trucks properly for highways speeds here in the U.S. I think it is a betrayal of sorts to note that the DMAX needs more gearing than the gasoline motor; it speaks directly to the well known shortcomings of a V8 diesel with something other than low end torque as its strong suit. > A 8.1 with a 4.56 and a 6 > speed would be a incredable tow beast. ANd if you through in a mild 6 [quoted text clipped - 5 lines] > (it is rated at 650 ft lbs) but 800 to 900 ft lbs out of a booste > Dmax will shorten trannies life. Both of those engines in the modified form you describe would trash the transmission behind them without significant mods to the transmission. Stop deluding yourself. > I can drag a truck out of a mud hole > with old 30 HP JD tractor that a Dmax truck would not be able to do in > same conditons. It is all in the proper gearing for load and engine, > not the engines type. Right and Wrong....... as in, yes, it IS all in the gearing for load and engine type. BUT..... Since JD tractors aren't geared for 65MPH pulling, you'll need to determine what would make the truck be able to pull the load at 65MPH, not 15MPH on a country road. You are stuck on gearing without looking at the parameters of the job to be done. SignatureMax "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) >>ok this is fair comparing a 1 ton p/u to a triaxle dump truck. heck if >>we're [quoted text clipped - 25 lines] > The SnoMan > www.thesnoman.com >> I am comparing a engine that is PROPERLY geared to the load not the >> vehicle. If you want a gas engine to pull equivalent to a deisel, you will need a big six, not an eight. It will almost certainly need to be "boosted", and it will need to have the valve timing and intake/exhaust geometry optimized for producing torque at lower RPMs., A 292 Chevy six handily outpulled most 327s and 348s in the sixties. A 409 would toast it. A 300 inch Ford Six outpulled any 302 V8 and most 351s.A 460 would toast it. A deisel's advantage is higher average cyl pressures than a gas engine (which has higher instantaneous cyl pressures) and better thermal efficiency (which translates to using less gas). A properly geared gas engine can do a good job of towing a TT if properly set up for the job. A deisel , also set up properly for the job, will do a better job in many ways, on less fuel. When towing, generally you want lots of grunt at low RPMs, you don't want to be winding 'em up and shifting, shifting, shifting to put the horsepower to the road. (671 anybody??) A 200 HP deisel that makes max power at 2400 RPM would be producing over 430 foot lbs of torque, and generally would produce that from about 1000 RPM (80 HP) or even lower. The (today's) gasoline 200HP engine would generally produce max power at 4800 RPM, where it would produce 215 ft lbs of torque. At 2800 RPM it may produce 250 ft lbs and 133 HP, while at 1000 RPM it would possibly put out 200 ft lbs and 38 HP. Some of the older gas engines, like the International 392 V8, put out 196 HP at 3600 RPM (just under 290 ft lb), and a peak torque of 316 ft lbs at 2200(132 HP). At 1000 RPM and roughly 280 ft lbs, it would develop 53? HP. So the big old international 8 would need to be geared twice as deep as the deisel to pull away, and the currrent 200 HP engine would need to be roughly 3 times as deep. SignaturePosted via a free Usenet account from http://www.teranews.com > > I am comparing a engine that is PROPERLY geared to the load not the > > vehicle. > > Your comparison has no merit when the question is about a pickup pulling a > load, not about a tri-axle. It seems to me that the question is about power, engine vs. load, not truck design for ride and handling. In that case, his comparison does apply. Has anybody noticed how this thread is posted to: alt.autos.dodge.trucks,alt.rv,rec.outdoors.rv-travel,rec.sport.football.college I haven't seen the OP, but I think it's obviously a.......wait for it......TROLL! I've trimmed the newsfroup list so this only goes to appropriate newsfroups. So, here's a technical question: Since buyers of diesel pickups choose them for low-end torque, why do they have turbochargers instead of superchargers? >So, here's a technical question: Since buyers of diesel pickups choose >them for low-end torque, why do they have turbochargers instead of >superchargers? Cost, reliability, longevity. SignatureFrank Tabor > So, here's a technical question: Since buyers of diesel pickups choose > them for low-end torque, why do they have turbochargers instead of > superchargers? Turbochargers are generally more efficient than a mechanically driven supercharger, and are capable of much higher boost pressures. SignatureMax "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) >> > I am comparing a engine that is PROPERLY geared to the load not the >> > vehicle. [quoted text clipped - 18 lines] > them for low-end torque, why do they have turbochargers instead of > superchargers? >>ok this is fair comparing a 1 ton p/u to a triaxle dump truck. heck if >>we're [quoted text clipped - 25 lines] > The SnoMan > www.thesnoman.com Granted, a gas engine properly geared can pull a significant load, but at what price in fuel economy?..... engine longevity? That is where the diesel is the engine of choice for heavy hauling applications... your anecdotal "evidence" notwithstanding. Mike > >ok this is fair comparing a 1 ton p/u to a triaxle dump truck. heck if we're > >comparing stuff like that then lets compare a festiva to a peterbuilt. [quoted text clipped - 6 lines] > Chevy on specail order starting in 06) it would surprize you what that > engine would pull effectively. nope it would not. ive never said a gas engine wouldnt get the job done. ive said for many reasons, fuel milage the main one, the diesel engine is the better chioce. The ally has a 3.1 first gear vs 2.48 > in 4L80 and a reverse more than twice as deep too which give the Dmax > a even bigger percived edge over a 6.0 with a 4.10 and a 4L80. They [quoted text clipped - 10 lines] > with old 30 HP JD tractor that a Dmax truck would not be able to do in > same conditons. as have i many times in the past few months around here with a 30 hp farm trac. surprising how many times these construction crews will get themselves stuck after a rain. It is all in the proper gearing for load and engine, > not the engines type. if all your concerned about is moving the load and not how much it will cost you to move the load then yes, its all about the gearing, and not the engine. ive driven gassers and diesels. my 99 v10 with 4.10's got around 10 - 11 mpg empty on the highway. i never figured it up towing. but i can tell you from the way the gas gauge moved it was roughly half that. now towing the same loads with 3.73's in the diesel im getting 14 - 15 mpg towing hmmm thats 5 mpg up with the load over empty with the old truck. and 19 mpg city empty with the diesel. cost of operation under the load is a HUGE factor. thats why all my vehicles are oil burners. > ----------------- > The SnoMan > www.thesnoman.com Signature-Chris 05 CTD 06 Liberty CRD Real trucks don't need spark plugs I just checked, and I do have the 3.42 rear diff in it. Great for around town, but not so good for towing. So should I: 1) Tow in "D" with the "tow/haul" switch on, or 2) Tow in "3"? Thanks > >With your 4L60E transmission always tow in 3rd gear. OD in that > >transmission is weak. Also, the frontal area of the new trailer [quoted text clipped - 20 lines] > The SnoMan > www.thesnoman.com > I just checked, and I do have the 3.42 rear diff in it. Great for > around town, but not so good for towing. So should I: > 1) Tow in "D" with the "tow/haul" switch on, or > 2) Tow in "3"? > > Thanks snipped Tow in "D" with the tow/haul on. The shift points come at higher revs and the clutch engages faster. It also will still go into overdrive but only when the speed is high enough and the driveline is not stressed. GM did a good thing when they brought out the tow/haul feature. Hugh >engine has to input 143 ftlbs of torque to make the same 100 ft lbs on >output shaft. (143 x .7 equal 100) so you can se how much you can load >tranny especaily with taller gears. >----------------- >The SnoMan >www.thesnoman.com May I ask you a couple questions about a rear differential ratio change, as you seem to know your beans about them? Here's the details: 90 Roadtrek Dodge B250 van, 318 cu. in. engine, Dodge trannie-auto/od, with a 8.25', 390 rear end, weight of vehicle is 7000 lbs, on a 3/4 ton chassis. I have the opportunity/expense (lol) to change ratios of the rear end. Is this 390 combo good enough, or is there a more 'closer to perfect' ratio, either higher or lower that might make a better difference in having a stronger, longer lasting, good fuel use ratio vs load hauling, etc. The unit will be driven never more than 65 mph, more likely 60 in most cases, most of the time is hilly or mountainous areas of the southern Appalacians. OD is used on Interstates, and off in hilly areas, etc. The problem now is it does not have any extra power for long hill climbs and will lose speed from 65 down to about 45, with the gas pedal to the floor and it downshifted once, on long climbs. Rpm's get really high during mountain climbs, speed dropping to 30 mph or less. It takes all the power that can be forced into it to pull those hills and mountains. Any advice on whether changing rear ratio recommendations will fix this problem or other info will be appreciated. Thanks SignatureHT >>engine has to input 143 ftlbs of torque to make the same 100 ft lbs on >>output shaft. (143 x .7 equal 100) so you can se how much you can load [quoted text clipped - 25 lines] > >Thanks A new rear end won't help. A bigger motor will. Going to a 4:10 rear end isn't going to provide all that much help. That motor is working as hard as it can. SignatureFrank Tabor >>mountain climbs, speed dropping to 30 mph or less. It takes all the >>power that can be forced into it to pull those hills and mountains. [quoted text clipped - 6 lines] >end isn't going to provide all that much help. That motor is working as >hard as it can. Well, I figured that, but still was grasping for straws...lol Thanks SignatureHT >>engine has to input 143 ftlbs of torque to make the same 100 ft lbs on >>output shaft. (143 x .7 equal 100) so you can se how much you can load [quoted text clipped - 25 lines] > >Thanks Followup question. Given I have an underpowered for the weight engine, a 3.90 ratio rear and a standard 90 Dodge 3 speed auto w. od transmission, what's my driving strategy gonna be, both on Interstate and in hilly/mountian areas? I have been driving with the OD on (that's the default condition) and switching it off on bigger hills, etc, or when the speed starts to drop off on hard pulls. The vehicle isn't used for towing, and is as I said, 7000 lbs. Can someone explain the rational behind wear vs, strain, vs mpg on using OD or not. Which condition puts more strain on the engine? the transmission? the rear end? What's recommended? I know when I drop it out of OD, it shifts down about the same amount as if I am not in OD and slow down and it shifts down normally, if that makes sense. SignatureHT >>>engine has to input 143 ftlbs of torque to make the same 100 ft lbs on >>>output shaft. (143 x .7 equal 100) so you can se how much you can load [quoted text clipped - 39 lines] >it out of OD, it shifts down about the same amount as if I am not in >OD and slow down and it shifts down normally, if that makes sense. If it isn't hunting, (excessive shifting in and out of OD), then leave it in OD. It will downshift when it needs to. Leaving it in 3rd with that low a rear end will cause you to run higher rpms unnecessarily and will really kill the fuel mileage. SignatureFrank Tabor > I've towed it about three times, and I was wondering how much of the > time I should spend in 3rd gear? How often does the cooling fan run > (HOT here in Texas)? What is the recommended towing speed? What mpg > should I expect? We have that transmission in our gas 2003 2500HD We have a 5er weighing 9,700 lbs. The truck has no named OD, but has D, 3,2, etc We tow in D except for going down steep hills when we put it in 3rd. Assuming yours is an automatic just leave it in D, except for going down steep hills, which you would do even without the trailer anyway. The truck will hardly notice a mere 4,000 lb trailer <G> Towing speed should be under 65mph I believe, due to the rating of the trailer's tires. AFAIK they can overheat and blow at higher speeds for too long (defined as when they blow!) Mpg will vary. A couple mpg less than without the trailer. Regards, Barry Thanks for the advice. I figured a lot of it was due to the added wind resistance, and I'll probably just have to get used to it. What kind of mileage do you get with your gasoline powered rigs? Maybe I'm just trying to set my wife up for buying a turbo Diesel of some kind. ;) > Thanks for the advice. I figured a lot of it was due to the added wind > resistance, and I'll probably just have to get used to it. [quoted text clipped - 3 lines] > Maybe I'm just trying to set my wife up for buying a turbo Diesel of > some kind. ;) You should see 12 plus mpg if you tow around 60 mpg. It's what I got with my '01 Silverado 1500 towing in tow mode, seldom in overdrive. My 26 foot TT weighed right around 6,500 pounds loaded. You don't need a diesel with your light trailer...unless you want one. With an equalizer hitch, you shouldn't even notice the trailer behind you. Going back to your original post, there is no good comparison between the popup and what you are pulling now. The TT is putting more weight on the trailer tires but the big difference, as others have noted, is wind resistance. You did right to install the extra cooling. Synthetic oil is a personal thing. In my opinion, the most important thing you can do for your tranny is keep the cruise control turned off; drive with your accelerator foot; an if you notice your transmission shifting a lot you should manually shift to the lower gear. The constant shifting and heat buildup is what damages transmissions. In heavy head-winds you might have to slow down and go to a lower gear. > What kind of mileage do you get with your gasoline powered rigs? I have no experience with your particular engine. However, during the early 90's I pulled a 21' Road Ranger with high frontal area with a Chevy PU with a 305 cu in engine. I also pulled a friend's 25 foot TT and noticed no real difference. Normal cruising with our trailer was around 9-10 MPG. Heavy headwinds dropped it to the 5-7 range. Smaller engines will suffer more in the MPG range than big ones. The problem with big engines (diesel excluded) is they get bad mileage all of the time. I just traded a 8.1L 2500HD Chevy for a like-bodied Duramax. The big engine would pull a trailer straight up the wall (well, slight exaggeration - but it had LOTs of power). Milage ran 10 town/13-14 highway/7.5 pulling our 31' Cedar Creek 5th wheel (12-1/2 foot overhead clearance)). We will pull with the diesel the first time this evening; but we have already seen 21 mpg highway and 15 in town. My trailer dealer and pulling friends tell me to expect 10-12 mpg while towing. > Maybe I'm just trying to set my wife up for buying a turbo Diesel of > some kind. ;) You don't need a diesel to pull that trailer. However, the smaller engine just demands more care in the way you drive and you have to pay attention to your transmission shifting and respond as needed. If you decide to go with a 3/4 ton diesel you get a lot more than engine. The bigger trucks have stronger suspension and generally heavy-duty everything. Both the 8.1L and the current Duramax GM products have the Allison transmission which is a great safety feature. The tow-haul mode and downhill braking characteristics will take good care of you and your family. We have taken our 8.1L/Allison over several Colorado and NM mountain passes. Our first trip took us over La Veta Pass in a DRIVING thundertstorm. I let the transmission do its thing on the way down and when we reached the bottom I wasn't a raving lunatic. That says a lot for that transmission. RonB > Thanks for the advice. I figured a lot of it was due to the added wind > resistance, and I'll probably just have to get used to it. [quoted text clipped - 3 lines] > Maybe I'm just trying to set my wife up for buying a turbo Diesel of > some kind. ;) We're getting 9.2 mpg towing a 30' travel trailer (with super slide) with an '03 Dodge Ram 1500, quad cab, Hemi engine and 5 speed automatic. This was mileage calculated when we came back from central Florida to central New York. These days I seldom run faster than 60 mph. We had an '02 Sierra club cab with a 4.8L V8 and automatic and towed a 26' travel trailer to Florida for two years. Got just about the same mileage as with the Dodge and current trailer. Hugh P.S. Sorry...its www.redlineoil.com But, read this page on Water Wetter so you are better informed about running LESS Glycol Coolant for better heat transfer : Red Line Oil: Coolants and Others Address:http://www.redlineoil.com/products_coolant.asp?productID=53 > What kind of mileage do you get with your gasoline powered rigs? I get around 8.3 MPG towing my 26-ft (actual) TT at 65 mph and around 10.9 solo, going back-and-forth to work and just running errands. (see sig below for specs) > Maybe I'm just trying to set my wife up for buying a turbo Diesel of > some kind. ;) Hehehe! That would pull your little trailer JUST FINE!! Signature:) JR 2000 Skamper Ultra 249 TT 2002 Chevrolet Silverado 2500HD Vortec 8100 - Allison 1000 my 2 cents. I tow a slightly larger TT with a '04 model Silverado extended cab with the same engine you have. It does have the factory tow package. I generally get 16-18 mpg. When towing my TT I get between 8-11, depending on speed and wind (amazing how a tailwind helps). I use the tow-haul mode on the tranny (basically bypasses OD). I agree with others that speed is the big factor, mpg decreases dramatically after 60 mph. I had a pop up previously, there is no comparison. I've towed at speeds up to 75 (not recommended) but find that I get there about as fast between 60 and 65 with much less stress on the rig and my nerves. Saves a lot of gas too. The rolling hills between Houston and San Antonio are little problem, but you will be surprised how much the truck works pulling any type of steep grade. Never had any problems with heat myself, maybe because I don't do much hill work. I would not feel good taking my rig through mountainous country. Get a set of equalizers for the trailer, and consider an anti-sway bar. If you have been pulling a pop-up you'll be amazed what happens when you get hit by a crosswind, or with the turbulence of an 18 wheeler passing you. This is much less of a problem at 60 mph. One more thing, check the trailer to see if the area behind the wheel well is protected from disintegrating tires from a blowout. Had that happen to me a while back and the tread ate a hole in the floor as it came apart. Would have been so easy to protect the area before that happened. Look under there, if it is not protected the time to do so is now. Just got back from Garner, it was only 105 at the Frio. Happy Trails. >I know my subject is kind of cryptic, and I apologize. Let me give some >more background: [quoted text clipped - 18 lines] > >Thanks for sharing your experiences. > I have a 2001 Chevy Silverado Ext Cab with the 5.3L V8. >I guess I was spoiled when I towed the pop-up. Yes, you were. > Cruising on the highway at 75mph was no problem. Except for the freakin' WHEELS on the popup! Sheesh! :\ > Towing the TT is of course a whole different story. I'll bet. How do you like towing that "wall" down the highway? It really SUCKS UP the gas, doesn't it? > It's UVW is right about 4000 pounds If that came from the factory specs, it's almost meaningless. Weight the trailer and be sure. You might be AMAZED at how "optimistic" the factory specs are. > we specifically went with that to make it lighter and easier to tow. You did the right thing. I suspect your pickup isn't overloaded, but it's probably getting close to the max. > I've towed it about three times, and I was wondering how > much of the time I should spend in 3rd gear? If you got a "lot" pickup, you may have gotten rather "tall" rearend gears. This will make towing in third necessary much of the time. Just keep an eye on the RPM and you'll be OK. > How often does the cooling fan run (HOT here in Texas)? Probably a LOT if not continuously in third on a REALLY hot day. > What is the recommended towing speed? In third gear? 3500 RPM. 60 MPH? I dunno... > What mpg should I expect? Third gear? 7 - 7.5 (yeah, it hurts) > I'm kind of anal retentive about my truck. That's not a BAD thing. Your truck will thank you for it. > Although I'm sure everything is perfectly normal, > I just don't know what to expect. Particularly if your pickup has "high" gears (numerically lower than 3.73) and you're towing a lot of time in third (not unheard of or necessarily BAD), it's gonna make a lot of noise and burn *A LOT* of gas. Don't let the transmission "hunt" (keep it in third), watch your RPMs and change fluids often. It'll be fine. It's working A LOT HARDER than it ever did. Good luck! Signature:) JR 2000 Skamper Ultra 249 TT 2002 Chevrolet Silverado 2500HD Vortec 8100 - Allison 1000 > > I have a 2001 Chevy Silverado Ext Cab with the 5.3L V8. ... > > It's UVW is right about 4000 pounds > [quoted text clipped - 6 lines] > This will make towing in third necessary much of the time. Just keep an eye > on the RPM and you'll be OK. For a benchmark comparison: I have the same truck (2002 GMC Sierra 1500 extended cab with 5.3L V8) and a TT that weighs 6,000 lbs (on a scale) when more-than-fully-loaded. My truck has a pretty tall rear-end -- I don't remember exactly, but it wasn't the optional 4.10. Otherwise, it's got all the factory trailering options -- aux trans cooler + HD alternator, rear suspension (which still manages to be nice and soft), and I don't remember what else. It tows like a champ. In mountainous terrain, it does spend a lot of time in 3rd. I did find one mountain where the road went straight up the steepest part; it was right out of the CG where I stayed, and I didn't have a running start. My poor truck had a tough time there, as the TT was definitely approaching 6,000 lbs that day. The TT was very low, and I recently raised it so I could get it in and out of my steep driveway; soon, I'll see if it's still as perfectly stable and easy to pull. >I know my subject is kind of cryptic, and I apologize. Let me give some >more background: [quoted text clipped - 18 lines] > >Thanks for sharing your experiences. I have a 2002 Silverado with 5.3 and factory tow package. I recently bought a 2005 Keystone Cougar 30' with 2 slides and towed it to Houston from Pensacola. I had no problem running 65, averaged 9 mpg and temp stayed left of center where it always stays without a trailer. I kept it in "3" and engaged the "Tow/Haul" button (which is what the owners manual suggests) and never had a problem. I once forgot and left it in "D" but quickly found that it shifted frequently. Trailer weighs about double what yours does so you should have no problem with yours. Good luck and enjoy. Alright folks - I appreciate all the advice. The reason I had posted the original topic was that I just didn't know what to expect. My Silverado has been a great truck, never a problem, and I knew what it "felt" like without towing for 5 years. I figured this would be the best place to come to check about everyone else's opinions and I wasn't disappointed. So all the caveats I had virtually discovered myself are pretty much valid. Don't tow much above 60 is one of them. That'll be hard for someone who's got a type "A" personality and wants to get there yesterday. ;) There are a couple of things: Since my truck didn't come with the towing package, I have no tranny temp gauge. I rely on the engine coolant gauge to let me know if something is amiss. The tranny fluid goes through one of the factory radiators, so it's not quite the same thing, but I'm probably alright. The temp needle hasn't really changed position from where it usually s without towing, but now the cooling fan runs more often. That was where some of my apprehension was coming from: The worry that my gauge might be malfunctioning. I also notice that engine oil coolers never come up much - is that not a big concern? I switched to synthetic simply due to the expectation of higher engine temps. It's also good info about the tranny overheating due to shifting around too much. I'll definitely keep that in mind and see how the rig runs. One last word about the Jayco: It's rated at 4000 UVW, and I know that they're a little optimistic with their ratings, but I doubt they would err by 2200 pounds. The towing capacity of my 1500 (5.3L, 3.42, Ext Cab SB) is 6200, so I should easily be within the rated capacity. I'm glad I talked to a buddy of mine who cautioned about twoing a trailer in the 5000# + range. That changed our initial search criteria from 28' TT to 23' hybrid. The latter saves about 1000#. We've been very happy with the Jayco so far - pretty much the same interior room as a bigger TT, since the beds fold up. There are a few drawbacks of course, but no big deal. Thanks again for everyone's help and suggestions. > One last word about the Jayco: It's rated at 4000 UVW, and I know that > they're a little optimistic with their ratings, Some mix up here? UVW is not a rating and is not what it weighs either. Should weigh a bit less than the GVWR when loaded for a trip. What is the GVWR for the trailer and what does it really weigh? (axle weight plus tongue weight = weight) The truck can probably do the job ok, but it is useful to know , eg, how close you are to the GAWR on the rear of the truck and the rest the weight figures wrt their ratings so you know how much more weight you can carry in the truck when towing the trailer. Also, eg how much water you can carry in the trailer. Regards, Barry I see where martin.schuessler@gmail.com contributed: >One last word about the Jayco: It's rated at 4000 UVW, and I know that >they're a little optimistic with their ratings, but I doubt they would >err by 2200 pounds. The towing capacity of my 1500 (5.3L, 3.42, Ext Cab >SB) is 6200, so I should easily be within the rated capacity. In the amount of time it took for you to type this long message you coulda got on the phone and located a scale. Having weighed the rig, you'd then KNOW how close you are to the rating. Be concerned about the GCWR (Gross Combined Wt Rating), because most of the weight of cargo in the truck must be deducted from the so-called max tow rating. You have the wrong gears for towing a TT, and probably should never tow in 4th (OD) except on long gentle downgrades. (BTDT - had a similar truck except with the 350 or 5.7L motor, absolutely gutless trying to tow, ate the tranny). Will Sill The Curmudgeon of Sill Hill snipped > You have the wrong gears for towing a TT, and probably should never > tow in 4th (OD) except on long gentle downgrades. (BTDT - had a > similar truck except with the 350 or 5.7L motor, absolutely gutless > trying to tow, ate the tranny). > > Will Sill The above is skewed advice Martin. The poster has no idea how strong the newer 5.3L is compared to the old 5.7L. Although having the 3.73 gears would be better, the 3.42 will do just fine towing your trailer. We had an '02 Sierra club cab with the 4.8L V8 and it had the same gearing but did have a tow package. We towed a 26', non slide, HR Alumascape trailer (UVW around 4,400 lbs) and the Sierra would tow in drive with the tow/haul mode on. Overdrive would cut in around 62 mph IIRC, shifts were more positive and mileage was around 9 mpg. I would suggest, if you don't have the factory tow package, you have one installed. The cooling fan clutch comes in three models. One is intended for a truck without A/C, one for A/C and one for towing. If you don't have the tow/haul feature, please do tow only in drive (3rd). The transmission you have is not nearly as strong as the one provided in the 2500 models. Don't be afraid of forcing a downshift on hills and locking it in by the gear selector. These newer engines don't mind turning at 4,000 rpm for trips up hills. Hugh |
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