What is power-to-weight ratio?
Power-to-weight ratio compares engine output with the mass it must move. More horsepower per ton generally means stronger acceleration potential. The inverse measurement, pounds per horsepower, is also common: a lower number means each horsepower carries less weight.
hp per US ton = horsepower ÷ (weight in lb ÷ 2,000)
lb per hp = weight in pounds ÷ horsepower
Curb weight or loaded weight?
Use curb weight to compare published vehicle specifications. Use actual loaded weight—including driver, passengers, cargo and fuel—to estimate a real driving or track configuration.
Does a better ratio guarantee faster acceleration?
No. Traction, gearing, torque curve, drivetrain loss, aerodynamics, tires and shift time also matter. The ratio is most useful as a simple comparison between broadly similar vehicles.