Competitors typically remove heavy or unneeded parts of the combines before competitions and reinforce the front, or header, of the vehicle.
[3] A vehicle is deemed eliminated once its header section is destroyed or the combine is immobilized.
[8] The vehicles used in competition often are 15 feet (4.6 m) tall and weigh up to 15,000 pounds (6,800 kg).
[5] Some competitions enforce rules about the height of the header, tire standards, age of the contestants, and the location and contents of the gas tank.
[5] Though some competitions offer prizes of $1,500, it is expensive to modify and maintain the combines and some winners lose money overall.