[wiredgeorge]

A lot of folks feel that high octane gas is somehow going to increase performance in their vehicle. Not exactly. Most people think that higher octane in gasoline supercharges the combustion in an engine cylinder, giving them additional power and performance. It is this misunderstanding of what octane actually does which leads people to spend more on gasoline than they really need to.

What does octane do?If you see a high octane rating for a given gasoline, what does that really tell you? That you'll get better mileage and more power? Or does it tell you something different?

The octane rating of gasoline essentially tells you how much the air-fuel mixture can be compressed before it will spontaneously ignite. Gasoline with an optimal octane rating performs best in an engine designed to run on that octane level. On a higher compression engine, it may be necessary to use higher octane gas so as to keep the air fuel mixture from combusting prematurely.

Using high octane gas in an engine designed for regular octane fuel may actually cause poorer performance. The one advantage of "premium" pump gas is that it may have a better additive package but you can always go to the auto parts store and buy a bottle of Techron. I kind of disagree with the broad brush statement that higher octane fuel with its higher cost is somehow superior to lower octane fuels.