What is the recommended Octane for the XC90? We have been putting 92 in ours. We have owned it for 3 months.

 

That is fine.

If you want once in a while you can put Regular in it.

 

Volvo would recommend 91 octane for all their vehicles. Turbo cars probably need it more than N/A cars. Of course the R platform needs 93+

 

Hello.

It depends what altitude you live at. At sea level, higher octane levers are beneficial, but as you go up in altitude, and there is less oxygen for combustion, regular unleaded will work. I'd still advise turbo engine cars (because they run so much warmer), to use at least 87 octane.

The better question is, which fuel brands should I be using? The lower quality fuels (like Safeway brand) are more likely to have dirt, water or other impurities in it verses say premium brands like Shell or BP/Amoco.

Good Luck.

Scott Kameron

 

Just use the highest octane there is, i mean, the volvo deserves it!

 

My 2006 V70R only gets fed Chevron 94 0ctane.With 231000 kilometres on the engine I’m not about to put in the cheap stuff.It may run ok on 87, but I would be nervous about using any boost.The car runs great on 94 and my spark plugs are a perfect tan colour.I would never forgive myself if I ended up melting a piston top for running cheaper fuel.At around $8000.00 for a new engine I think the extra $5-6 dollars a fill is cheap insurance.There is no alcohol in the Chevron 94 octane, bonus.if I park the car for a few months during winter.Alcohol is corrosive!

 

For any forced induction engines you want to put the highest octane available aka Premium. Your engine will compensate down to lower levels if needed but you won't be getting the best performance from it in doing so.

 

92 is fine, just use what's highest at the pump. The higher octane rating on gas is for the compression. Using a lower octane rating can lead to early detonation of the fuel before the piston is at optimal position. Your engine will absolutely not compensate if you put lower gas in. If you want your car to take care of you, take care of it and put the correct fuel in it.

 

Perhaps you misunderstood.
The knock sensor – a small piezoelectric microphone which detects knock inside the engine which comes from below optimal octane or compromised fuel etc... will send a signal to the ECU to retard the ignition timing if it begins sensing knock. Retarding the ignition timing reduces the tendency to detonate, but also reduces power output and fuel efficiency. You would have to put pretty low octane fuel in for it to detonate (cause knock). 91 Octane will not cause this. So what I meant is that there are safeguards in place to prevent your engine from detonating...

We'll be running 91 or 93 in ours depending on fuel stations when we need fuel. Always premium here.

 

Yeah little misunderstanding, I thought you were saying that the car will magically work fine with the regular gas if you use it enough. I agree 91 definitely wont cause that. I think the pumps near me have 93, that's what I use.

 

I was actually curious if you'd get more gains out of the Polestar ECU upgrade if you ran 93 vs 91 octane...
We got the Polestar "option" thrown in for free on ours...

 

this has to be some sort of a record for a zombie thread. Original topic was posted in 2006! :-) Since I'm here, my two cents is read the owners manual - there's subtle language for each model/engine that will either say "recommended" octane or "required". Highly tuned engines require premium, lesser tunes will show as "recommended". Even with knock sensors and a modern engine management system, highly tuned cars can ping and damage valves/pistons over time...

 

LOL! I didn't notice it was a zombie thread till you pointed it out! Too funny.

 

Rule of thumb, if it's forced induction just put in premium. Why risk damaging and having to replace an engine over saving pennies at the pump? Being that these new models are turbocharged AND supercharged use premium all of the time! Says it right in the owners manual as well.

 

If the owner's manual says 91 is required, then it is required. If it is recommended, then running 87 won't damage anything. There is so much misinformation about octane on message boards.