Well, I can run down the highway and lower the rpms to say 1500 in double OD and not see any haze, or hint that the engine is lugging. On flat ground I was able to get down to 1200 @55mpg again double OD. When I had to accelerate the engine came up to 1600-1700 and with only a hint of haze.....I didn't mat it, ijust slowly applied foot pressure...................now to the other end of the rpm gauge. This cam will pull all the way to 4k but you can feel it level off just before, which was expected But in my truck I was already doing 130mph,so im please. The only thing I swapped from the H2 that I was running was the cam, clutch and tappet cover.