Originally Posted by chev49
mine is 2600 @ 72 mph.. top speed... 12x22.5 tires.
I have 11-22.5 Mine will do pretty near 80 I think....havent tried anything about 70 though. I'm gunna call foul on your tach or speedo. Even with a different size tire I dont think you could get that low of an RPM. I get 9mpg, but I live in the mountains. 1800 is the peak torque curve for this engine. If I could get 1800rpm at 62mph [which is all I run], I would be well pleased.