As name suggests, it's racing fuel (m) (archive)

For actual racing, usually at the drag strip. The extra octane is helpful with ultra-high compression engines, and/or engines with severe forced induction. It will not increase the performance of your BMW one whit; as with all octane ratings, if your car isn't designed to use it/need it, you're just wasting money. Worse, some of those racing fuels are leaded (or at least they were as recently as the early 90s), which of course would do a number on your catalytic converter.

Note that octane is a measure, not of flammability or energy per unit of volume, as is widely believed, but rather of resistance to premature burning. Octane prevents fuel from igniting too quickly--uncontrolled, premature ignition of fuel, you may recall, is what causes detonation. Simplistically, the higher your compression ratio, the more likely detonation becomes, and thus the more octane you need. Thus, more octane itself doesn't give you more power; rather, it allows you to build an engine that makes more power. Too much octane can actually lead to poorer performance, since you don't want your gas to be too resistant to ignition.

Stick with 91 or 93, and you should be fine.

Just saw it today at the Unocal near Bundy and Pico in West LA tonight... 100 octance, and **$4.30/gallon**. They call it "Racing Fuel"

Crazy... I think it might be aimed toward the kid-racer market... only on one pump.

Any thoughts? I wonder if it would increase performance at all?

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