Re: 89 octane OK in 2.8L V6?

[Chris Newbold <cnewbold@transarc.com>]

BOEING377@aol.com wrote:

> The manual says use only high octane gas (92 or higher).  I tried 89 and no
> knocking was detectable.  Am I getting less power or hurting fuel economy?  Is
> the knock sensor retarding the timing or does the car run fine on this lower

The knock sensors are compensating for the lower octane and, as a result,
you're getting slightly less power. It may or may not be noticable.

The risk you run is that you may exceed the system's limit for ignition
retard and start to knock. I doubt the system can retard the timing enough
to cause heat damage, but I'm sure the engineers had their reasons for the
91 octane minimum...

-Chris
1993 90CS