A tool that estimates the horsepower delivered to a vehicle’s wheels based on the horsepower measured at the engine’s crankshaft. This calculation typically factors in drivetrain losses, which occur as power is transferred through the transmission, differential, and axles. For example, an engine producing 300 horsepower at the crank might only deliver 250 horsepower to the wheels due to these frictional losses.
Understanding the difference between these two horsepower figures is crucial for performance analysis and tuning. Crank horsepower represents the engine’s raw power output, while wheel horsepower reflects the actual power available to propel the vehicle. Knowledge of these figures enables more accurate performance comparisons between vehicles, informed decisions on modifications, and a clearer picture of drivetrain efficiency. The concept has evolved alongside automotive technology, becoming increasingly relevant as vehicles become more complex and tunability increases.
