Has anyone ever tried any of the 100 octane unleaded gas sold by Unocal? At select locations they have 100 octane unleaded racing fuel - $5.00 a gallon Nascar fuel - identical to unleaded pump gas but with higher octane. Some also have 95.5 octane which is 1/2 100 and 1/2 91 octane.

Has anyone ever tried them? I know my car runs stronger on 91 than on 87 or 89 octane, but would 95.5 or 100 make a difference? Would it shave any 10ths off of a 0-60 or 1/4 mile time?

If you are interested go to www.76.com - click on "Store Locator" - then find a station that sells "Racing Fuel"

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Nathan Valles, Black 855R, Tint

I tried them all and it make no different in the car perfomance that I know ..

we have a 1994 850 turbo and it run strong with 87 octan gas. no knock no problem

personly I think most car nut like to spend extra moneys on their gas this making feeling good...

But the fact is how fast can we go ??? where can we run our 1/4 mile ???

without get a ticket ??? the 850 turbo is more than fast enough for what we are using for daily ...

Do not mean to put down high octan gas... just want to said for daily used we this will not make any different....

Higher octane retards the burn rate of fuel. This is designed to prevent preignition (knock) in high compression engines. If your engine is normally aspirated, octane above regular (87) or midgrade (89) will probably hurt performance. In unmodified turbo engines, the specified 91 (a European spec) isn't available so we use the slightly slower burning super (93). Again, anything above that will be meaningless or counterproductive. Actually, if your octane is too high I'd be concerned about burning valves, as it's possible a little combustion could still be in process when the exhaust valve opens.

If on the other hand you have a modified engine (chipped, large-bore turbo, etc.), a higher octane would be desireable. Think of the compression ratios racing fuels are designed for; unless you're approaching these kinds of numbers, you'd just be wasting your money.

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(98 S70 T5SE misc mods, mostly lighting) (92 940GLE)

I have filled a couple of times with 94 Octane from Sunoco (and always do it a couple of times with any car I have owned) ad I have not seen any difference. I doubt you would see any with the 95.5 Octane. 100 Octane? You probably will. But not worth $5 a gallon...

My uncle took his 1998 BMW 528i to Greece, permanently (I had driven his car many times while it was here in the States). In Greece, he usually filled it with Regular Unleaded, which is 95 Octane. He or I could not see the difference from when the car was in the States. Same thing when we used Super Unleaded which is rated at 96.5 Octane. But whenever we used SuperPlus Unleaded, rated at 98 Octane, we "thought" that the car accelerated quicker. Never timed it, officially, but it felt quicker.


Yannis
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2001 V70 T-5M, Classic Red/Graphite Lthr., Sunroof, Cold Weather, Dolby Surr. Sound, Rear Spoiler, 17' 'Tethys' alloys

Interesting but unforunately there's only 6 states that sell racing gas, non anywhere near me. We can buy racing gas at our local dragstrip as well but my HP cars compression isn't so high that I need it. I would need it if I were running 12/1 compression ratio pistons however.
For you car, you can try it but at that price I highly doubt that you'll think it's worthwhile. It'd be beneficial if you were running a racing engine with very high compression but a normal stock engine, no.