Net horsepower is defined as the usable horsepower remaining after deducting engine losses.

• A. the horsepower at the wheels
• B. the total horsepower before any losses
• C. the horsepower produced at the crankshaft
• D. the usable horsepower remaining after deducting engine losses

Answer: (D)

Net horsepower represents the usable power left after subtracting engine losses such as internal friction, pumping losses, and accessory-driven drag. This means it reflects how much of the engine’s output is actually available for useful work once those internal losses are accounted for. It’s different from horsepower at the wheels (which also includes drivetrain losses) and from horsepower produced at the crankshaft or gross/indicated horsepower (which are measured before all engine losses are deducted). Therefore, describing net horsepower as the usable horsepower remaining after deducting engine losses matches the concept.