>From: "J. Walker" <JWALKER@ua1vm.ua.edu>

>the best 'rule of thumb' i've heard is to run the cheapest octane you can
>THAT DOES NOT MAKE YOUR ENGINE 'PING'. usually, this is what is recommended
>by the manufacturer. but not always. i currently also own a h*nd* (shame!)
>for which 87 octane is recommended ... but it pings on local 87 octane. so i
>'have to' run 89 octane in it (to get what i consider 'normal' running and
>performance).

I share a ride with a woman who has an '89 Dodge Colt.  It recommends 87 octane
and that is what she always uses.  I have noticed that it pings and hesitates
but she has always lived with it.  Once when it was my turn to fill up I put
in 92 octane when she was not looking and her problems went away.  But that
was just one time.  I told her that most manufacturers often sent up an certain
engines to run on 87 octane because that is what people will buy.  I also
mentioned that all our VWs say 91 octane but seems to run fine on 89.  I don't
know about 87 since we never use that except for our lawn mower and tracter.

Jonathan
jdove@gsvms2.cc.gasou.edu