Why do horsepower and torque cross at 5,252 RPM? They're interwoven, important for the speed and acceleration of your vehicle, and the desire of every gearhead. You take your car to the dyno, and you notice that torque and horsepower cross paths at 5,252 RPM. You add some modifications to your car, increasing both power and torque, and yet again they both cross at 5,252 RPM. Why is this, and is it meaningful? This video discusses the physics, the theory, and the math behind this magical number.