Re: Regular or Ethel ???

[James Marriott <marriott@micron.net>]

Paul R Anderson wrote:
> 
> Bob, I have to disagree with Phil.  If your car has CIS E-III, easily
> identified by
> the flare end instead of banjo bolt fuel lines, higher octane will
> probably
> help.  I don't remember what the recommended octane is but
> I think it's 91.  Your engine control will lean out the mixture and
> will advance the ignition timing until it misses or knocks and will
> then back it off.  The higher the octane, the more it can advance the
> timing and the better fuel economy and power you will get.

Not _always_ the case. Keep in mind:  the higher the octane, the lower
the (volumetric) energy content. For example, my non-knock '87 4kq will
get worse mileage with 92 octane (R+M/2 method) than with 87.

> The only thing I can say is to try it.  I have the same car and I
> often alternate between tanks.  I am collecting data on the fuel economy
> related to average speed and octane used.  When I have collected enough
> data to run some good statistics on it, I'll share it with the list.
> Any comments?

Ahhh, a scientific plan. The best way! :-)

cu
James