A common misconception (one that
13 Jul 2001A common misconception (one that I’ve had at one time, as well) is that using higher octane gas will give you better gas mileage and better engine performance.
This, of course, is a fallacy – and if you have a low compression engine, it can actually deteriorate your engine’s performance.
I found a great webpage that discusses the specifics of how gas octane rating can affect the performance of engines designed for street driving
Well, that link is way out of date. I even updated it once, but the URL has been relocated or lost once again.
So here is a good page on howstuffworks.com that explains the same thing.