I enjoy watching videos of the tractor pulls. Have noticed that those monster rear tires are wrinkle walls. Didn't realize you could do that on dirt. Not like a drag car, but you can see the tires in photos & they are wrinkle walls. Am always amazed at the class that features 5-6 supercharged engines, or turbines, or old Allison airplane engines. So cool to watch. Those tractors are first cousins to drag cars. You really can say those are drag races.