Here's a pretty good primer on octane:

http://en.wikipedia.org/wiki/Octane_rating

Seeing 93 being 3cents more than 91 last time, I decided to give it a whirl. I feel no difference at all in performance or fuel efficiency. I'll be going back to 91...

in germany bmw explicitly recommends 95oct and higher. but it just doesnt matter cause there is no difference in the price with '91

The octane rating is different between USA and Europe.

Why do people think higher octane = more power?

In the East Coast, 93 is pretty much the standard rating for premium. In some cases, 91 is available. There's a 7-11 in Richmond that has 5 grades of petrol. I pay for the 91, which is mildly cheaper than 93, and as far as I can tell, has no downside.

Well, higher octane gas does make a power difference. By how much, it depends on the engine. I also have a Subaru WRX STi which is turbocharged. If I put 87 and I floor it, it will detonate (especially if the weather is warm) and it will run like crap. If I put 100 racing gas, I might even see a +30HP difference of the dyno. Turbocharged cars love high octane gas... !

We know that it's more complicated than that but using a high octane fuel makes a difference when the engine is producing its maximum power. Maybe you don't push yours enough to feel a difference ;)

Actually, why'm I commenting in this thread? :confused: This subject "is so done..."

Please no more discussion!!


Lock this thread!!!!



:thud: