Difference between revisions of "Horsepower"

Jump to navigation Jump to search
4 bytes removed ,  17:23, 6 January 2007
Line 135: Line 135:
In the United States the term "bhp" fell into disuse after the American Society of Automotive Engineers (SAE) recommended manufacturers use '''hp (SAE)''' to indicate the net power of the engine, given that particular car's complete engine installation. It measures engine power at the [[flywheel]], not counting drivetrain losses.
In the United States the term "bhp" fell into disuse after the American Society of Automotive Engineers (SAE) recommended manufacturers use '''hp (SAE)''' to indicate the net power of the engine, given that particular car's complete engine installation. It measures engine power at the [[flywheel]], not counting drivetrain losses.


Starting in 1971 automakers began to quote power in terms of '''SAE net horsepower''' (as defined by standard J1349). This reflected the rated power of the engine in as-installed trim, with all accessories and standard intake and exhaust systems. By 1972 U.S. carmakers quoted power exclusively in SAE net hp. The change was meant to 'deflate' power ratings to assuage the [[auto insurance]] industry and environmental and safety lobbies, as well as to obfuscate the power losses caused by [[smog|emissions]]-control equipment.  
Starting in 1971 automakers began to quote power in terms of '''SAE net horsepower''' (as defined by standard J1349). This reflected the rated power of the engine in as-installed trim, with all accessories and standard intake and exhaust systems. By 1972 U.S. carmakers quoted power exclusively in SAE net hp. The change was meant to 'deflate' power ratings to assuage the auto insurance industry and environmental and safety lobbies, as well as to obfuscate the power losses caused by [[smog|emissions]]-control equipment.  


SAE net ratings, while more accurate than gross ratings, still represent the engine's power at the flywheel. Contrary to some reports, it does ''not'' measure power at the drive wheels.
SAE net ratings, while more accurate than gross ratings, still represent the engine's power at the flywheel. Contrary to some reports, it does ''not'' measure power at the drive wheels.

Navigation menu