[CREWZIN]

BB,

In order to measure HP loss you'd have to put you car on a dyno. Have you ever seen a dyno pull in person. The engine is taken to red line a few times to get accurate readings. Putting a lower grade gasoline in the tank and having the computer retard the timing would mean your redlining the engine in a non-optimal configuration.

First a couple of pulls with premium gas to get a base-line reading then again when you use up that gas and fill up with a lower octane gas to find out what you already know.

Will it damage anything? Let us know when you try it.