Date: Tue, 18 Feb 2003 12:41:47 GMT From: "Fred W." <Fred.Willsnopsamammyrealbox.com> Subject: Re: What fuel for best highway gas mileage? '90 - 9000T
"Walt Kienzle" <wkienzlenopsam.net> wrote in message news:b2s1eb01jq5nopsams2.newsguy.com... > On my 1991 9000T (2.3) I get the best highway gas mileage with premium gas, > probably because the engine is running at a high RPM at expressway speeds. > Interestingly, my 3L Taurus SHO gets the best highway gas mileage using > mid-grade or a regular/mid-grade mix. The only way this would be possible is that the lower grade gas is causing pinging (detonation) and the anti-knock sensor in the SAAB is retarding timing as a consequence. There is the same amount of energy in 1 gallon of gas regardless of octane value. The higher rated stuff just burns a bit slower.