Yesterday morning on the way to work I passed the 4K mile mark on my '08 Sierra Denali. Had to run a couple of errands mid-morning and it was VERY apparent that the truck was more responsive to the throttle and seemed to have quite a bit more torque and power.

My question is - I'm wondering if there is some sort of "limiter" in the OEM engine calibration which won't allow full power until a certain pre-determined mileage?

Has anyone else noticed this?