Horsepower
Horsepower (hp) is a unit of measurement that tells you how much power an engine produces, which determines how fast a race car can go and how quickly it can accelerate.
The term "horsepower" was invented by Scottish engineer James Watt in the late 1700s when he was trying to sell steam engines. He needed a way to help people understand how powerful his machines were, so he compared them to horses—the main source of power at the time. One horsepower is officially defined as the power needed to lift 33,000 pounds by one foot in one minute, though today we use it simply to describe engine power.
In motorsport, horsepower is one of the most important numbers you'll hear. It directly affects a race car's performance on the track. More horsepower means faster speeds on straightaways and quicker acceleration when coming out of corners. This is why teams spend enormous amounts of time and money trying to squeeze every last bit of power from their engines.
Engine power is measured using a special machine called a dynamometer, or "dyno" for short. The dyno tests how much force and torque the engine produces, then calculates the horsepower. There are actually different types of horsepower measurements. Imperial horsepower (hp or bhp) equals about 745.7 watts, while metric horsepower (PS, cv, or ch) equals about 735.5 watts. Brake horsepower (bhp) specifically refers to the power output after accounting for energy lost to friction inside the engine.
Different racing series have wildly different horsepower levels. Top Fuel dragsters are the most extreme, producing an incredible 10,000 to 11,000 hp. Formula 1 cars generate around 1,000 hp by combining a small 1.6-liter turbocharged engine with electric motors. NASCAR Cup cars currently produce about 670 hp, while IndyCar engines make over 700 hp from their 2.2-liter twin-turbo V6 engines. Even small racing karts can produce up to 100 hp from tiny two-stroke engines.
Several factors influence how much horsepower an engine produces. Engine design and tuning play huge roles—different teams can extract different amounts of power from similar engines. The amount of turbo boost, compression ratios, and fuel quality all affect power output. In many racing series, regulations strictly control these factors to keep competition fair and costs manageable.
Racing organizations often impose horsepower limits for important reasons. These restrictions help ensure that races are decided by driver skill and team strategy rather than just who has the most powerful engine. They also improve safety by preventing speeds from becoming dangerously high, and they help control costs so smaller teams can compete without spending millions on engine development.
Understanding horsepower helps you appreciate the engineering behind motorsport and why different race cars perform the way they do. When you hear that a Formula 1 car has less horsepower than a Top Fuel dragster but can still lap a circuit faster, you're learning about the complex relationship between power, weight, aerodynamics, and handling that makes racing so fascinating.