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Engine measurement history

The historical context of engine measurement, including the transition from SAE gross to SAE net horsepower.

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Jan 26, 2026
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What is a percentage range of horsepower difference between SAE gross horsepower and SAE net?

The difference between gross and SAE net horsepower is not a fixed number but typically falls in the range of about 10–25% lower for SAE net compared with SAE gross; many authoritative and enthusiast ...

Feb 2, 2026

At what pounds per horsepower ratio does a car start to seem fast to most people

Per the reporting available, enthusiasts and practical calculators point to a rough zone where cars begin to "feel" fast: roughly 20 pounds per horsepower and below tends to be perceived as lively, wh...