Why?

[Tim Rogers]

cowboydren wrote:

>>> Why on earth would you put 87 octane in your "sporty" car? That amazes
>>> me.

>> Well, unless you've adjusted your cylinder pressures (advanced timing,
cams, whatever), there's no reason to spend the extra 10 cents per
gallon.  It's not like there's majic camel pee in 89 or 91 that isn't in
87 that's going to make your fully-stock car run better.<<

This is true.  Unless you have done something to increase your vehicle's
tendency to knock, (like advanced timing, increased compression ratio,
boost, etc.) you can actually make less power and have worse fuel economy
with higher octane.
Why?  Higher octane fuel burns more slowly.
(At this point, Bruce will confirm or deny this.)
So only use as much octane as you need.

Tim Rogers
-93 NX T-top -needs wiring work
-91 NX - Racecar-to-be
-75 Silverado - Rusty Tow Beast