According to Diesel Power Magazine, the heaviest dump truck is the Caterpillar. It has a curb weight of 307 tons, a gross operating weight of 687.5 tons and a maximum capacity of 380 tons. It has 3,550 horsepower and a top speed, when fully loaded, of 42 miles per hour.
Most dump trucks are so large that their parts are shipped and built on-site. Dump truck diesel engines may weigh up to 25,000 pounds. The average top speed of these trucks is 40 miles per hour, and their average weight is 497 tons. The Terex Unit Rig has the most horsepower at 3,750.