the diff between STD and SAE is that STD (standard)is what the car is actually making on any given day given outside air temp and density altitude. SAE is the Society of Automotive Engineers. SAE corrects for the above stated in the STD, making it a level playing field. A car with alot of mods will make less power then a car with less mods, if the car with more mods is say at a 6000ft altitude and a 90 degree day. At a higher elevation the air molecules are farther apart, hense less air = less power. Same goes for outside air temp. Hot air is less dense, hence less power. with that said, just to help you understand better, on a cold day with high barometeric press(29.92 or above) my car may make 520 rwhp STD. The next day it may be alot hotter and pressure may be 29.92 or below. This day I may make 501 rwhp STD. If the dyno operator sets the graph to SAE, the numbers should be the same from both runs ( in theory).
