It's under the hood of every car, truck and SUV (unless the vehicle is electric), but how many people really know how an engine works? Do you know a spark plug from a fuel injector? Test your auto smarts in our engine quiz.
Surprisingly enough, horsepower actually does refer to the power of horses. But over the years it’s become a valuable measurement for all kinds of machinery. Learn how horsepower is calculated and what it means to the automobile industry.