[Aerkuld]

I usually reckon on 400 to 440 miles before I stop to fill the tank in the '87 which is somewhere in the 23-27 mpg range depending on how empty the tank is when I stop, but usually about 16 gallons give or take. None of that is really long highway cruises or around town traffic, just country road driving.
In the 996 I did have the on board computer showing something in excess of 32 mpg on a run between Charlotte and Augusta one weekend at a average speed of about 70mph (nearly all freeway). High 20's or low 30's are pretty typical on long runs. Daily commute is normally about 21-23 mpg though.
The 944 always seems to do about 24-25 mpg no matter where it goes.