I have a 2004 S80 with the 2.9 non-turbo engine. I have been told any octane is ok, but the owner's manual says to run premium. Please advise.

Hi there. For what my two cents are worth to you. I drove a 1990 740 Turbo for three years. I drove it on BP's 98 octane. That 2.3litre engine took off when it needed to and the car started well with the high octane.

I now drive an S80 2.0 litre Turbo. I still use the BP 98 octane fuel. The car drives very well. It is not a patch on the 740 for power, take-off or otherwise. The S80 is a very sauve and refined car. But,

the new owner of my 740 noticed that my old car was starting to get difficult to start. It took him a while to find out that one of the people using the car was putting 91 octane fuel in it.

I notice that a lot of people try and do a cause, campaign and crusade on me when they try and tell me that they don't notice any difference between 91 and 98 octane fuel. In normal driving, you won't notice too much difference between the fuels. When starting or burying both feet into the accelerator to pass another vehicle-that is when you notice what you pay for.

Go with 98 octane. You won't regret it. You might regret putting cheap fuel into you car. If you are an environmentalist, 98 octane has less sulphur in it. That feature has to be good for you and your car.

Cheers

I own '99 S80 T6 and have benn using 87 octane since the gas price spike. I have noticed no difference in performance. However, I only drive around town and commute on the highway. I see no difference except in my wallet. I currently have 97K on my baby and the ECM(thottle Mod) still is running fine.

You really didn't mean 98 did you? I've never seen anything that high uless I go to the airport and buy jet fuel. 89, maybe. Where do you live and where would they offer this high octane gas for an auto? The highest rating I've ever seen where I am (Tennessee) is 93.
--
1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon

The rest of the world uses a different octane measure than the good ol' USA. Our 93 = their 98.
If anyone uses Avgas in their car, they can kiss their cat converter good bye! Avgas is still leaded!!!! BTW, jet fuel is clean kerosene, not gasoline.

The S80 without a high pressure turbo can run on regular with no adverse effects. It says so in the owner's manual.

Klaus
--
98 V70Rawd(108Kmi), 95 854T(88K mi), 75 164E(173K mi)

Thanks for clearing that up...now I know. It is very confusing. Clean karosine in jets, huh? Wow..didn't know that either.
--
1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon

You would do best to use exactly the grade that the owners' manual specifies. The knock control system may let you get away with a lower octane, but performance will be less. Presuming you are in the USA, if the recommended octane is 91, you can alternate fill-ups with mid-grade (89) and premium (93). The mixture in your tank should be just about right. Be sure to use a branded fuel (Chevron, Exxon, etc.).

Don't worry about the octane, worry about the ETM.

My S80 T-6 drives just fine on 87 octane. Again, I see no reson to throw my money away on the higher octanes!