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Car Forum / Volvo Cars / September 2004Volvo 850 - gas type?
Do all Volvo 850s require premium gas? As gas prices have risen plenty in the last year - I do not want to purchase a vehicle that requires premium. From the 850s on - which require stricltly premium? My old 240 and 740 did not. (Side note - the 740 GLE is the BEST car in the world - yes, I know some of you are raising your eyebrows). Thanks, Tmuld. > Do all Volvo 850s require premium gas? None do. They may perform better and get better gas mileage with premium, but they have a knock detector that will adjust the timing to the grade of the gas. I have had a '93 and '95 850 and a '01 V70XC and never used premium in any of them. No problems. I like to run a tank of Chevron with Techron every once in a while, or get a can of Techron and add it myself, but never had any problems.  SignaturePardon my spam deterrent; send email to rhodyman@earthlink.net Cheers, Steve Henning in Reading, PA, USA Owned '67,'68,'71,'74,'79,'81,'87,'93,'95 & '02 Volvos. The '67,'74,'79,'87,'95 and '02 through European Delivery. http://home.earthlink.net/~rhodyman/volvo.html >> Do all Volvo 850s require premium gas? > [quoted text clipped - 4 lines] >of Chevron with Techron every once in a while, or get a can of Techron >and add it myself, but never had any problems. My '95 850 manual says: "Volvo engines are designed for optimum performance on premium with octane AKI 91 or above (AKI = RON + MON/2). Minimum octane requirement is AKI 87." This implies that although 87 is OK, the higher (premium 91 or above) would be 'better', yes? Any harm done in alternating tankfuls, or should I just stick with one rating? Jay >>> Do all Volvo 850s require premium gas? >> [quoted text clipped - 12 lines] >would be 'better', yes? Any harm done in alternating tankfuls, or >should I just stick with one rating? It's about efficiency. The knock sensor will adjust the timing OK, but it is compromising an engine that was designed to be able to use premium, so it will necessarily make the engine less efficient - less power and less mpg. Depending upon the price difference between the grades of fuel, you may actually find it cheaper to run on the more expensive stuff. There wouldn't be any point in alternating tankfuls. SignatureStewart Hargrave For email, replace 'SpamOnlyToHere' with my name >There >wouldn't be any point in alternating tankfuls. Actually, if one didn't let the tank go dry between fill-ups, alternating tankfuls would raise the average octane level, since there would be at least some 91 octane in there with the 87. I don't know if I would waste the effort. 20 cents more for premium times 15 gallons is $3 per tankful difference if it's completely empty. I would spend the extra for increases performance. KennyH Horsepower is cheaper than therapy. >>There >>wouldn't be any point in alternating tankfuls. > >Actually, if one didn't let the tank go dry between fill-ups, alternating >tankfuls would raise the average octane level ...or lower it. SignatureStewart Hargrave For email, replace 'SpamOnlyToHere' with my name > I don't know if I would waste the effort. 20 cents more for premium times 15 > gallons is $3 per tankful difference if it's completely empty. I would spend > the extra for increased performance. You've made a direct hit, I think--and the logic of your argument is even more persuasive here in Europe. Not sure what you're paying but not long ago we heard the shock! horror! stories of 'two bucks a gallon for gas!' in America so let's use that price for the purpose of illustration. If regular is $2.00 and premium is '20 cents more', then your '$3 per tankful difference' represents a 10% increase. In Finland (where I am), today, a typical price for regular is 1.159 euros per litre and for premium it's 1.189 euros per litre. That translates (at today's exchange rate) to US$ 5.35 and 5.49 respectively, per US gallon. The price differential here is only 2.6% more for premium. Assuming your 15 gallon ( = 57 litre) fill, that's $80 for regular and $82 for premium. Does it make any sense to scrimp for a lousy two bucks per tank, on a bill of 80 bucks?!? My '95 850T is happier on premium, and when my Volvo is happy, I'm happy. :-) (Of course, I'm one of those guys who changes oil every 3000 miles, too.) One last point: you say '15 gallons...if it's completely empty'. The tank capacity on my '95 is 73 litres, which is more like 19.3 gallons. Maybe the US models were different? cheers, Henry Has anyone ever done a test - see the mileage difference on a base 850 with 87 then with 91? There is a difference of abotu 20 cents/litre of gas here. I think one US gallon is 3.8 litres. The difference is substantial - but if mileage was equitable - it might be worth it. Anyone try this or have info on where I can find this info? Thanks, Tmuld. > It's about efficiency. The knock sensor will adjust the timing OK, but > it is compromising an engine that was designed to be able to use [quoted text clipped - 4 lines] > may actually find it cheaper to run on the more expensive stuff. There > wouldn't be any point in alternating tankfuls. Can't say on an 850, but my '95 Passat VR6, over 100 miles of comparable driving was only about 2 MPG better....not enough from an economy standpoint. >Has anyone ever done a test - see the mileage difference on a base 850 >with 87 then with 91? [quoted text clipped - 17 lines] >> may actually find it cheaper to run on the more expensive stuff. There >> wouldn't be any point in alternating tankfuls. Ron/Champ 6 1963 8E5 Champ (Champ 6) 1962 Lark Daytona Convertible (Boomerang) 1995 VW Passat (Vanilla..yuk) 1994 Volvo 850 (Tilley) Uh, I left a '0' off...1000 miles! >Can't say on an 850, but my '95 Passat VR6, over 100 miles of >comparable driving was only about 2 MPG better....not enough from an [quoted text clipped - 28 lines] >1995 VW Passat (Vanilla..yuk) >1994 Volvo 850 (Tilley) Ron/Champ 6 1963 8E5 Champ (Champ 6) 1962 Lark Daytona Convertible (Boomerang) 1995 VW Passat (Vanilla..yuk) 1994 Volvo 850 (Tilley) > Has anyone ever done a test - see the mileage difference on a base 850 > with 87 then with 91? I have with both my '93 and '95 with highway driving and saw at most a one mpg difference between 87 and 91 octane. Definitely not significant. SignaturePardon my spam deterrent; send email to rhodyman@earthlink.net Cheers, Steve Henning in Reading, PA, USA Owned '67,'68,'71,'74,'79,'81,'87,'93,'95 & '02 Volvos. The '67,'74,'79,'87,'95 and '02 through European Delivery. http://home.earthlink.net/~rhodyman/volvo.html > My '95 850 manual says: "Volvo engines are designed for optimum > performance on premium with octane AKI 91 or above (AKI = RON + [quoted text clipped - 3 lines] > would be 'better', yes? Any harm done in alternating tankfuls, or > should I just stick with one rating? Your manual says it all. No harm will be done if you stay at or above 87. There is no point in alternating. What would make a more sense would be when you fill up to use part one octane and part the other IF you saw a difference. Gas stations don't have a rule that says you can only use one grade. You can mix grades at the pump. You will have to pay twice at a "pay at the pump" station, but who cares if that is what you want. Your manual just says you will get better power and, perhaps, better economy from 91 octane or better. The experts, "Click & Clack," say to use the grade that gets the best miles per $ for you. Any better grade is just a waste of money. My '65 Austin Healey Sprite would get 30 mpg on regular and 35 mpg on premium. It turned out I got the same miles per $ no matter which grade I used. I haven't notice that effect with my Volvo 850s. SignaturePardon my spam deterrent; send email to rhodyman@earthlink.net Cheers, Steve Henning in Reading, PA, USA Owned '67,'68,'71,'74,'79,'81,'87,'93,'95 & '02 Volvos. The '67,'74,'79,'87,'95 and '02 through European Delivery. http://home.earthlink.net/~rhodyman/volvo.html Thanks Stephen, It makes sense to me. Jay >> My '95 850 manual says: "Volvo engines are designed for optimum >> performance on premium with octane AKI 91 or above (AKI = RON + [quoted text clipped - 20 lines] >premium. It turned out I got the same miles per $ no matter which grade >I used. I haven't notice that effect with my Volvo 850s. >Your manual just says you will get better power and, perhaps, better >economy from 91 octane or better. The experts, "Click & Clack," say to >use the grade that gets the best miles per $ for you. Any better grade >is just a waste of money. There's an exception. Turbo engines, like my 850's, have their maximum boost limited by the output of the knock sensors. So, higher octane = less knock = higher boost = more power. To reply, please remove one letter from each side of "@" Spammers are VERMIN. Please kill them all. > There's an exception. Turbo engines, like my 850's, have their maximum > boost limited by the output of the knock sensors. > So, > higher octane = less knock (correction) = higher boost = more power. Conversely, lower octane = more knock correction = lower boost = more economy. SignaturePardon my spam deterrent; send email to rhodyman@earthlink.net Cheers, Steve Henning in Reading, PA, USA Owned '67,'68,'71,'74,'79,'81,'87,'93,'95 & '02 Volvos. The '67,'74,'79,'87,'95 and '02 through European Delivery. http://home.earthlink.net/~rhodyman/volvo.html >> There's an exception. Turbo engines, like my 850's, have their maximum >> boost limited by the output of the knock sensors. [quoted text clipped - 3 lines] >Conversely, >lower octane = more knock correction = lower boost = more economy. In terms of pure economy, it all depends upon the price difference between the grades of fuel. A turbo is not about simply chucking more fuel into the engine. The more boost (or compression) you are able to employ, the more efficiently the fuel will burn, which means extracting more usable (kinetic) energy out of the same amount of fuel. This is a fundamental principle of engine design. The limiting factor is the ability of the fuel to withstand the initial combustion pressures without detonating spontaneously before the flame front reaches it. This is what we usually hear as knock, although there can be other causes for it, too. An engine will be designed to use a fuel that will not detonate at a given maximum pressure. This is governed by compression ratio and turbo overpressure. If lower octane fuel is used there is a danger of knock, and in order to prevent this, the ignition point is retarded so that P[max] occures later in the descent of the piston and will consequently be lower. This will result in relative inefficiency. An engine that needs to retard its ignition timing to prevent knock is not using the ideal fuel to exploit its combustion pressure fully, and cannot be working at optimum efficiency. Most drivers tend to use the extra energy that a turbo releases as HP rather than torque (many turboed cars are set up to maximise this), which may mitigate against achieving greater mpg. One problem with turbochargers is that they don't start working well until they are spinning fast, so at lower speeds, running less boost, a turboed car (which often tend to have lower compression ratios) will be naturally inefficient. SignatureStewart Hargrave For email, replace 'SpamOnlyToHere' with my name > >> There's an exception. Turbo engines, like my 850's, have their maximum > >> boost limited by the output of the knock sensors. [quoted text clipped - 35 lines] > (which often tend to have lower compression ratios) will be naturally > inefficient. And in the real world a turbo'd gasoline engine will almost always get worse fuel economy than the same engine without a turbo. Both of mine get several mpg lower than the N/A Volvos in the family even driven conservatively. Worst economy is on regular, mid grade gets the best mileage, and premium allows a bit more power for around the same mileage as regular, I usually run mid grade. The 240 has no knock sensor and pings on regular at 14 psi so this mostly applies to the 740. >And in the real world a turbo'd gasoline engine will almost always get worse >fuel economy than the same engine without a turbo. Both of mine get several >mpg lower than the N/A Volvos in the family even driven conservatively. Therein is the crux. Drive a turbo conservatively and it naturally tends to be inefficient. Driving in a way that makes the turbo work is not necessarily conducive to better mileage (though thermal efficiency will be improved). SignatureStewart Hargrave For email, replace 'SpamOnlyToHere' with my name > >And in the real world a turbo'd gasoline engine will almost always get worse > >fuel economy than the same engine without a turbo. Both of mine get several [quoted text clipped - 4 lines] > not necessarily conducive to better mileage (though thermal efficiency > will be improved). Well I can say with certainty that using the turbo frequently will not increase mileage regardless of what it does for thermal efficiency. I once managed 13 mpg average for a tank of gas in my 240T. Best I've ever gotten was just over 24mpg highway. >> >And in the real world a turbo'd gasoline engine will almost always get >worse [quoted text clipped - 11 lines] >managed 13 mpg average for a tank of gas in my 240T. Best I've ever gotten >was just over 24mpg highway. It's reasonable for a turboed car to return poorer mpg than it's equivalent N/A car, but it is surprising to see the variation in mileage you get. 24 mpg is an improvement of nearly 85% over 13 mpg. That is far better than my best-over-worst figure in a N/A 740 (not entirely a fair comparison, since I run on LPG). My best mileage is about 30% better than my worst; I don't think any of my 200s did any better. Presumably the big difference you see is down to the turbo doing it's stuff when it's on boost. SignatureStewart Hargrave For email, replace 'SpamOnlyToHere' with my name I think the overiding factor as to why a turbo car returns worse fuel consumption will alwys be the 'grin factor' a turbo car has. I have a 99S70 T5 SE and have had a worst consumption of 22mpg (UK gallons) and a best of 38mpg.... The former on country lanes whilst grinning like a Cheshire cat and the latter whilst on motorways cruising in traffic at 40-60mph with virtually no stop start stuff (very rare that happens in the UK!)... Both were over a distance equivalent to 1/2 tank of fuel so not entirely definitive... As for turbo cars being less efficient when driven gently, this is a common myth. A turbo car can be more economical than an equivalent non turbo car as it can provide air to the engine without the engine having to draw it in (that vacuum reading has to be worked for by the engine). As the turbo utilises otherwise waste energy contained in the still rapidly expanding exhaust gasses it relieves the engine of the need to 'suck' air into the combustion chamber. Unfortunately for a petrol engine this applies to a very narrow range of engine operating speeds and is typically a few hundred revs near where the turbo provides positive pressure to the inlet manifold (and positive pressure over around 2psi is where economy suffers). If you look at the diesel world (ok, so its a different principle involved but some of the concepts hold), the turbo diesel engine almost always seems to be more economical than the non-turbo equivalent. To be fair to the turbo engine though we should compare apples with apples and not apples with pears. If we look at the power outputs of a turbo engine and an equivalent power output NA engine the NA engine almost always loses out. This is because a larger engine has inherently more frictional losses than a smaller one (larger bores, longer strokes and/or more cylinders), thus a small engine with lower losses and a turbo will generally be more economical than a larger higher friction one. >>> >And in the real world a turbo'd gasoline engine will almost always get >>worse [quoted text clipped - 20 lines] > better. Presumably the big difference you see is down to the turbo > doing it's stuff when it's on boost. > In terms of pure economy, it all depends upon the price difference > between the grades of fuel. A turbo is not about simply chucking more > fuel into the engine. If the turbo is kicking in then you aren't getting any economy. SignaturePardon my spam deterrent; send email to rhodyman@earthlink.net Cheers, Steve Henning in Reading, PA USA http://home.earthlink.net/~rhodyman If your mixing and matching 87 and 91 then why not put a whole tank of 89 octane in?? We always used to run our 740 on 89 octane, with premium 91 when it was time for a long trip (didn't make a difference for just around town).... We have 87,89, and 91 at almost every filling station around here, maybe you don't have the three grades everywhere where you live? >> My '95 850 manual says: "Volvo engines are designed for optimum >> performance on premium with octane AKI 91 or above (AKI = RON + [quoted text clipped - 20 lines] > premium. It turned out I got the same miles per $ no matter which grade > I used. I haven't notice that effect with my Volvo 850s. I wrote: > There is no point in alternating. What would make a more sense > would be when you fill up to use part one octane and part the other IF > you saw a difference. Gas stations don't have a rule that says you can > only use one grade. You can mix grades at the pump. You will have to > pay twice at a "pay at the pump" station, but who cares if that is what > you want. > If your (you're) mixing and matching 87 and 91 then why not put a whole > tank of 89 octane in?? Think out of the box. Try mixing 87 and 89 if 87 doesn't work as well as 89. If that is not a problem, then stick with 87. SignaturePardon my spam deterrent; send email to rhodyman@earthlink.net Cheers, Steve Henning in Reading, PA, USA Owned '67,'68,'71,'74,'79,'81,'87,'93,'95 & '02 Volvos. The '67,'74,'79,'87,'95 and '02 through European Delivery. http://home.earthlink.net/~rhodyman/volvo.html I'll just stick with my premium 91 then... MUCH easier, almost worth the few dollars per tank not to have to do all that work. >I wrote: > [quoted text clipped - 10 lines] > Think out of the box. Try mixing 87 and 89 if 87 doesn't work as well > as 89. If that is not a problem, then stick with 87. > I'll just stick with my premium 91 Have you tried 100 octane AvGas. If you want to blow money, you might as well do it right. We don't have that here... I'm in Ontario, Canada... the highest i've seen is 95 Octane at a Pioneer station and 94 Octane at a Sunoco. If you think "blowing" money on a car that can use premium fuel is the correct term, that's your opinion... If the manual is recommending 91 then why not use it, I'm not going to have my timing retarded and performance reduced just because at the absolute minimum 87 Octane will function in the engine... Not after going to the dealer and having the service guy say to me "that's probably one of the nicest running 10 year old cars i've ever worked on" Where do I get this "AvGas" anyways?? >> I'll just stick with my premium 91 > > Have you tried 100 octane AvGas. If you want to blow money, you might > as well do it right. > Where do I get this "AvGas" anyways?? From any small airfield, it's aviation fuel, used in piston engine aircraft. Doesn't it still contain lead? Or at least did recently. >> Where do I get this "AvGas" anyways?? > > From any small airfield, it's aviation fuel, used in piston engine > aircraft. > Doesn't it still contain lead? Or at least did recently. I dunno, only time I've ever heard of people running it in cars was for race cars. Yes, it's called 100LL for "low lead". > Doesn't it still contain lead? Or at least did recently. > > >> Where do I get this "AvGas" anyways?? > > > > From any small airfield, it's aviation fuel, used in piston engine > > aircraft. > > Where do I get this "AvGas" anyways?? > > From any small airfield, it's aviation fuel, used in piston engine aircraft. You could buy racing fuel at most any track too... What does Cam-2 go for now days anyone know? I admit I was wrong, I read my owners manual it does say premium. I just put in ~10 gallons in the ~17 gallon tank, saw no performance change, 2 or 3 more tanks will tell... To everyone I told 87 was ok, I am sorry, I might have been wrong. I will report on my result in a few weeks. You're all forgetting the altitude factor as well. At 5280ft our pumps all offer lower octane levels. > Do all Volvo 850s require premium gas? > [quoted text clipped - 11 lines] > > Tmuld. |
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