much of diesel's economy is found from the lack of a throttle plate. (commonly refered to as pumping losses) while, I don't "floor" the car when hypermiling, I try to keep it in closed loop. yea the sentra is paramount in being able to accelerate from as low as 25mph in 6th but I never used more then 1/2 throttle. the other thing is keeping the fuel trims low. since the sentra can do a short term trim between -15 and +15% and that's on top of it's LONG term trim of +/- 20% which is why the car can run 85% ethanol on stock fuel system.