Gas Mileage
The only data that I have accumulated on our Class C V10 is on a trip we took to Colorado where we had a schedule to keep. You can check out Kirk's formula, but it looks to be accurate. We tried to maintain (with cruise) an rpm of 2500 (a speed of 65 mph). Our best mileage on flat freeway was 8.2 mpg. However, a stretch with strong headwinds reduced mileage to around 6.0 mpg (the worst). We averaged a speed of 52 mph.
I'm inclined to believe that engine manufacturers have chosen 2000 rpm as the "normal" driving rpm. On the vehicles that I have, that will equal 55 mph to 60 mph.
At today's prices ... I'd rather be _park_ed! :approve: