[Gary C]

actually what i have found results in best mileage (for the cuiser anyway) is driving at a varying rate of speed, ranging from right at the 65 mph speed limit to 5 under to sustaining 70-72mph.
How i drive, as i accelerate briskly, but not full throttle, more like 1/2 to 3/4 throttle to the speed limit, then clutch in a coast.
I have a somewhat finiky driving style, that i picked up driving a friends hybrid car on a bet that I couldn't make a tank of gas go over 550 miles. Sure enough I was able to average 53mpg with mixed city/highway use, when he averages right around 44-47mpg. Also the fact that I have been fairly active in the super low consumption vehicles that the local high school builds as the shop i work for does a lot of parts supply for them, and with talking to the instructor of the class, as well as other groups involved, I've been able to borrow their quick short bursts then coast theory and apply it to my driving when I'm just putting around town and not in the mood to put the foot through the floor board.. in a manner of speaking.
Coasting up hills, but acclerating to a somewhat higher speed than the posted limit on a downhill leading to an uphill and then clutching in saves on the fuel consumption as your not luging the car uphill, you're merely helping it accelerate downhill and letting it coast uphill, where upon you crest and resume a short quick burst of acceleration to bring you back up to the limit. Yet another thing which *decidely* helps is that I stay out of boost on the highway, and my commute is typically 87 miles each direction, at a constant speed limit of 65 for 60 miles of the commute, then it changes over to 55 once i cross the IL state line.
there is a bit more to it, but that's the jist of it. Every tank (save for the ones when I have been at the drag strip, or just romping on the car, like it was meant to be driven) for the past ~8000 miles has been ranging from 28-32 miles per gallon for pure highway driving, where with city/highway driving I'm typically right at the 26/27 mark. Admittedly, it's NOT the fun way to drive the GT, but when I've put over 10,000 miles on the cruiser in the past ~2 months, and that's abnormally low mileage for me. On average in a typical month I'll rack up ~5-8000 miles.[8)]soo it does take some effort to maintain the mileage and drive with that style, but it does put more money into my pocket book, which means more money for go fast mods (ironically enough).