On 5/21/05 5:35 PM, "Dennis" <guskersthecat@YAHOO.COM> wrote:

> There is zero benefit running 91 octane fuel in an engine with low
> compression, and no knock sensor (stock WBX).  High octane fuel only makes a
> difference in the 10 or 10.5:1 compression engines out there that can
> advance/retard timing dynamically to control detonation.  They will run more
> advance with high octane fuel meaning more power, cleaner combustion.
>
>

There was an interesting item on the news the other night about octane.

Less than ten percent of vehicles need the top two grades.

30 percent of vehicles are using the top two grades.

Almost all brands of gas on the market now contain additives to satisfy even
the most stringent auto mfr requirements for cleaners, etc.

Shell and Texaco both have published info that says to check your owners
manual for what grade you need but there are users that are just afraid to
use anything but the best even when it is actually not for some newer
vehicles.

Lower grade fuel is just standard markup for price.  Higher grades have
added profit margin added in.

jimt