MPH is power, ET is how you get the car down the track. But either way the advertised HP numbers are strictly based on the amount of nitrous flow. If you flow X amount of nitrous, you will make roughly this much extra power. It's not a hard and fast number and because nitrous effects different motors different ways. It adds torque, so if it loosens up your way tight converter, the car will leave harder and run quicker.........BUT, the mph is how much power it actually added.

If you go 12.50 on one run and 12.30 on the next, because the car spun, but run the same mph.......did you have more power on 12.30 run? Some seem to want to debate, but MPH is power......period