How many HP is needed at the axle of a semi truck?

The amount of horsepower needed at the axle of a semi truck depends on various factors such as the truck's weight, terrain, and desired performance.

For general highway transportation, semi trucks typically require around 400 to 500 horsepower at the axle. This allows them to maintain highway speeds, navigate moderate hills, and carry moderate loads.

For heavy-duty applications such as hauling oversized loads or operating in mountainous regions, semi trucks may require up to 600 or even 700 horsepower at the axle. These trucks are equipped with more powerful engines and drivetrains to handle demanding loads and challenging terrains.