there may be a post already up about this so im sorry if this is a repeat, but im just curious what kind of gas do some of you use in your volvo 850. i have a '93 and im using 87 but i plan on moving up to a higher grade soon and stay at the higher grade before winter comes. Also what kind of gas mileage do all of you get? with what i have now, im getting a little less than 20 MPG.

 

I use Regular(87) even though owning a turbo model probablly means you could be safer with a higher octane rating to help prevent detonation under boost, but with my driving habits I rarely push the engine in my car and I'd rather save the 10 cents per litre for what the difference between 87 and 91 is in my area.

-Mike

 

Greetings from Chicagoland.

I only use high-octane (92 or higher) fuel, as my 850 has turbocharged engine (B5234T). For any 850, I probably wouldn't use regular 87, though you may not feel much difference. For turbo, knocking/pinging is the primary reason for using premium fuel. However, for NA engines using 87 fuel wouldn't damage anything, unless if you hear knocking.

Fuel consumption on my 850 is pretty bad, as it is turbocharged and I mostly drive it for short commutes (besides, Volvo uses heavy-gage steel and this affect fuel economy but in a crash Volvo would survive better). However, I usually keep the conditions of tyres (correct pressure, tread wear, balance and correct rotational direction) & alignment impeccable.

Additionally, I use Valvoline synthetic blend 10W-30 oil. For colder climate, 5W-30 is usually recommended, but after a few minutes of idling the oil temp goes up and 5W-30 may become too thin, especially for turbocharger. I work on airplanes as FAA-certified tech and turbine engines use full synthetic oil, and automotive turbochargers are identical to jet engines in basic operational principle. One of the largest advantages of synthetic oil is protection under extreme high-temp and pressure, and this is a good choice for turbine bearing. I only use synthetic-blend, as I do not do much hard driving. However, someday when I'm lucky enough to buy a new car, I would use full synthetic.

Good night,


JPN

 

I've used nothing but 87 in my ' 94 850 Turbo Wagon. Around town I see around 20mpg and on the highway between 25-28mpg, although I have gotten in the 30's once. I've never gotten any pinging from 87. - AB

 

yea overall it looks like using any type of grade is fine unless, like a few of you mentioned, you hear knocking or any other noise that doesnt seem normal. and i like the idea JPN of how you can use 5W-30 in cold climates. Ive never really understood what people could possibly use 5W-30 for, but now i get the idea.

 

Gasoline
Shell Super Premium or Exon Super Premium

Oil: Mobil I Synthetic 10w-30

 

I run 87 in my NA 855. I get low 20s for pure city driving and 27+ for Hwy.

 

We use Regular 87 in our 1997 NA 5-cyl. We have found that it does better on Exxon than the No Name station. We get about 20-21 City and 24-27 on Highway. We have 209k on it. We use 5W30 oil.

 

Isn't when the temp goes up, 5w or 10w will be the same? Only when just starting the car 5w will be thiner than 10w? Correct me if I wrong, I am learning.

 

Ive been wondering about this for awhile now.. which grade is better.. Ive been using 91 or higher for some time now. Ive noticed one obvious difference, the car runs much smooth on higher octane. Lower octane it never feels like its running exactly right, just weaker if that makes sense, espically around town on the highway its almost the same. Ive been too scared to run 87 for fear of damaging something. But from what I see on here i should be fine, it is a 96 NA 855(100K) . And the extra mpg would be awesome.

Heres what I dont get...My perious car was a 95 NA 855 (150k) but it felt much more willing when on higher grade gas, it felt more responsive when I ran it hard. This 96 feels rather sluggish when compared. What was so differant if anything? 10v vs. 20v?. I hear the O2 sensor replacement does a world of difference, performance feel and gas milage. That and the fuel filter is something I need to do.
Thanks

 

Hello Mr. NA850ESTATE,

I did a bit of research on the type of fuel you should use, and here's my findings & my prejudice:

Usually, European cars require premium fuel, since in Europe the lowest grade (regular) fuel is rated at 95 octane rating (for those living in Europe, correct me if I'm wrong). However, for NA engined vehicles regular 87 would suffice. In general, high-performance engines require premium fuel, engines such as turbocharged, variable valve timing, DOHC, etc... The primary reason for using premium fuel, as other people have noted, is anti-knock property. Most modern cars, however, come with knock sensor and the ECU adjusts ignition timing to avoid knocking (in theory anyway).

For a turboed engine, I myself wouldn't use 87 fuel, but some people have noted that they never had problem using 87 on their 850 turbo, so the difference may be negligible. But for NA engine, I am not sure if premium fuel is worth the money. For European cars, it may be worth it, but European manufacturers that sell cars overseas should know local fuel quality, so I would simply follow the owner's guide as to which fuel to use.

Unless you experience severe knocking, you would not damage anything by using regular fuel.

>I hear the O2 sensor replacement does a world of difference, performance feel and gas mileage.

I do not have a definite answer as to this question. A new O2 sensor may or may not make much difference, it probably depends on the car. I once had an Accord (1988 model) and it ran fine even with the O2 sensor disconnected (but it didn't even start when I disconnected the coolant temp sensor). If you have a code for O2 sensor on your 850, then it might benefit by installing a new O2 sensor, but they are about $160-$200 each, and my 850 turbo has 2 of them ($$$).

Whatever parts you decide to replace, make sure to go with OEM or of higher quality parts. As for O2 sensors and fuel filter, I would go with Bosch.

I hope this helps.


JPN

 

Hello Mr. stevejanosik,

In regard to your question, yes, 5W-30 & 10W-30 give you the same performance at non-winter climate, in theory. However, the "-30" for 5W-30 can be misleading, as the wider the range, the thinner the oil for multi-grade oil in general. Wider-range oil also seems to have more tendency for the viscosity to change. However, I am not an oil specialist, so if there's someone out there who knows about engine oil better than I do (such as this person: http://www.bobistheoilguy.com/), please correct me.

It may not make a world of difference whether you go with 5W-30 or 10W-30, but I avoid 5W-30 based on my prejudice.

Oil & fuel selection is often based on a person's preference, and as long as you feel comfortable with something, that's what you should use. I currently use Valvoline synthetic blend 10W-30 and so far the engine seems to be happy and there is no oil leak. As for the fuel, I use 91 (92) or higher octane rating. Again, these are based on my personal preference + info from the owner's guide.

The most important thing to keep in mind regarding engine oil is to change regularly with name-brand oil & filter (MANN filter for 850), regardless of the brand, viscosity rating or the type of base oil (regular/synthetic) you currently use.

This may not have answered your question accurate enough, I'm sorry if I didn't clear your question.


JPN

 

We use 87 octane (occasionally 91) but no higher. We drive the our vehicles "briskly" and they perform just fine!