Why power-to-weight beats horsepower
Acceleration is force divided by mass. A 155 hp car that weighs 2,350 lb has about the same lb/hp as a 300 hp car at 4,550 lb, and in a straight line they'll be close. Power-to-weight is the fairest single number for comparing cars of different sizes.
Count the driver
Spec sheets list curb weight: full fluids, no people. On a light car, a 175 lb driver adds about 7–8% to the real weight, which is why light cars feel slower with a passenger. Leave the driver in to compare real-world numbers.
Rough benchmarks (lb per hp, with driver)
- 20+ lb/hp: economy car territory. The fun is in carrying speed through corners.
- 13–20 lb/hp: classic light sports cars and hot hatches.
- 9–13 lb/hp: proper performance cars.
- Under 9 lb/hp: supercar or serious build territory.
Want this as 0-60 and quarter-mile times? Use the 0-60 calculator.