I went on a nice road trip on tues, came back today, did 1300 km or 800mi. The 7 averaged about 10 L/100 km at a constant speed of 140km/h, 85 mph with passing mostly done in third to 7500rpm and 2 top speed runs (200km/h with 2 persons + luggage).
I was just thinking, at what rpm is it best to cruise in the 7? 140 km/h is 3400 rpm because the secondaries engage at 3500 or 3800 rpm, not too sure on that. Is it better to drive under 3500rpm or over? I think under but just making sure.

 

the 2ndarys come on at 3800, I believe the engines are most efficent at 3500rpm, atleast the 89-91's are. speed depends on which model you have (different rear ends)

 

3500 in a GTU/GXL is about 85 mph in 5th.
that sounds high doesnt it? what about all the drag? I would think about 55 mph.