Very low mpg, help plz

[911monty]

Originally Posted by Mike689

On 6th gear going 65mph the RPM is around 2.5k. Should I be using 5th gear then?

Yes; Listen to your engine and feel the pressure you are using on the throttle. The engine will communicate back to where it wants to run. You will have much better results. I have driven my 2.5 into So CAL down the 215 rarely using 5th gear and have gotten 32 calculated freeway. I believe you are so low in RPM the knock sensor is retarding the ignition timing. Try keeping at 3.2k +. I don't think your plugs are an issue since you just bought car so had to pass CA smog. Of course new plugs are always good.

PS; I used to have an air cooled 911 with weber carbs hat would load up below 3.5k. This was during the famous 55mph speed limit days. I used to have to shift constantly between 2nd and 3rd that car really hated that speed limit. Now at 90 Yahoo!