Engines were not and are not measured at the "wheels". SAE has always measured at the crank/flywheel. Before 1972, they were measured without accessories (Gross SAE)after 1972 they were measured with accessories (Net SAE). All done on a Engine dyno. That's the basic story. Atmosphere is taken into account. Manufacturers or dealers would never want "AT The Wheels" ratings and they were supposed to be stating SAE test numbers, albeit they did fudge a little. The testing done at the wheels started when folks wanted to know how much their performance parts added to the engine. Nobody wants to take out their engine to test on a engine dyno so they tested before and after on a Chassis dyno, hence: "At The Wheels". This was never a scientific measurement due to transmission/drivetrain drag, etc. but it would give you a percent Delta Number. Bartamos.
Last edited by bartamos; 07/02/2010 7:26 AM.
