I have searched the forums and have found no definitive answer on this. The instruction manual says my 2006 S60 2.5T requires premium gas. has that been the experience of users? Is it performance or actually protecting the car that requires this? Only one station in my town still sells non-ethanol gas and I doubt that will last very long. Is it important to use Premium, non-ethanol premium, or some other combination?

 

This is odd, since the owners manual for our 06 V70t tells that minimum octane requirement for that identical power train (I assume low pressure turbo non-R, auto trans) is 87 octane. Recommends premium for best performance. I think RON number is 94, but it could be 93, for this recommendation.

Premium gas exists mostly to resist detonation/engine knock/pinging. Modern cars have knock sensors which will dial back the timing if engine knock occurs. So you'll lose a few horses when that occurs. Will premium gas make your engine last longer? Not if premature detonation isn't a problem. That's the pebbles rattlling in a can sound when its not too bad, and the hammer hitting the head when it is horrible.

P.S. Congress is forcing ethanol blends down our throats, and I'm not referring to Jack Daniels, either. Farmers love the subsidy, and it makes the members of Congress look "green". It will cause trouble with much older engines that used different seals, rubber compounds, carbs, etc. On the other hand, the octane rating of ethanol is in the low 100's.

 

I take it you are saying if I don't hear a noise, I can use any fuel I want without negative consequences?

 

Running a high octane gas in a car that is not tuned for it is useless. But if the manual recommends it, that means the car is tuned for it. I actually have only been using 89 in mine... but I'm going to go check out the manual and see what it says.

 

When my wife fills it, she uses regular. I tend towards midgrade since premium is usually 20 cents per gallon more here. And when I've used 94 octane, I don't feel 10% power increase or 10% mileage increase. It will run on regular w/o knocking at all. I suspect 5% decrease at most in power and economy, if that. I do, however, use Techron at 5000 mile intervals -- the pour in kind.

 

I have 2006 S60 2.5T. I drive 700 to 1200 miles a week, I keep detailed maintence and fuel mileage records in addition to "seat of the pants feel". My car seems to run best by alternating tanks of econemy with tanks of mid-grade, no improvement noticed or measured with premium. Of course your mileage may very.

 

Yes, run 93 and only 93. Our vehicles (including the 2.4 t and 2.5 t) are tuned for it. Your cost per mile will be LOWER running higher octane gas as you will get better MPG.

 

We've been running 89 (mid-grade) in ours with no problems. Of course the wife is driving it most of the time and she'll never see 3500 RPM's. If you are on the hammer a lot, then the 93 is the way to go...if not, the lower grade is fine.

 

I found That when I use 87 octane my air flow sensorlight comes on,sine I srtarted with 91 octane all seems o.k. does any one have the same problem

 

all seems ok with 91 octane gas

 

On my 05' s60 2.5t, I've always been using 89 octane and consistently get 28mpg when I do the math. My daily commute is mostly highways, 92 miles round trip. I've used 91 octane but didn't notice anything as far as performance and MPG's

 

I have used good old reguar 87 octane and notice zero difference to premium 91.

A few premium gasolines have the advantage if not using ethenol, like Shell, Candian Tire, and Costco but that's anothger story.

Even before today's Variable Valve Timing, automobiles would adjust timing automatically so as not to knock or ping, let alone today.

If using regular gas would effect longetivity- they would have said. As for performance, I do not find much difference.

87 is fine in my opinion, just fine.