You might call the “Super Stock” an unlimited version of the “Farm” appearing tractor classes. Although they may appear “stock” on the outside, this class produces many times over their factory rated horsepower. As the name implies, diesel is the only fuel allowed in the Diesel Super Stock (DSS) division. These machines produce around 2,500 to 3,000 horsepower with their “stock engines” having up to four turbochargers flowing the air mixture. They weigh 8,200 pounds.
The Light Limited Pro Stock (LLP) division comes in at 8,200 lbs and closely resemble the normal 10,000 Pro Stock Tractors.
The Limited Pro Stock (LPS) division is a tip of the hat to the younger days of Pro Stock Tractor pulling. Limited to a 4.1 turbocharger, 640 cubic inches, and 9,500 lbs, this class has become a hot-button topic with the fans.
The Light Super Stock (LSS) class is a very colorful division in that many manufacturers are represented, such as Case-IH, John Deere, Agco Allis, Oliver, Massy Ferguson, Ford, and even Deutz. Unlike all the other classes that are born and breed from the agricultural fields of America, the LSS division features machines that both utilize diesel and alcohol as fuel choices. Weighing in at 6,000 pounds, the wheel speeds and wild rides are sure to please the crowds.
Modified Tractors began as farm tractors with non-tractor engines and grew into fully custom machines with multiple engines and power plant types. All divisions of the Modified class use a maximum of a 20″ drawbar and 30.5″x32″ tires. The Light Limited Modified class weighs 6,000 pounds with no turbines.
The Modified Tractor (MOD) class is an engineer’s dream, as the goal is to get four Hemi’s, three Turbines, or Allison Aircraft Engines to sing in harmony, in pursuit of putting the power to the track. Tipping the scales at 7,400 lbs, the competitors in this class must use every ounce they have to their advantage. Fans from across the country, pack the stands for a chance to watch these machines throw dirt with the power of over 10,000 horses.
10,000 PRO STOCK
Pro Stock Tractors (PS) are truly the brand-loyal, die-hard tractor pulling enthusiast. These machines top out at a maximum of 10,000 lbs and may bolt on a single turbocharger to an engine that can be built up to 680 cubic inches in displacement. Using a combination of diesel fuel and water injection, these smoke-billowing monsters contain some of the more legendary teams in the sport.
The Super Farm (SF) division is the closest tractor to stock you will see. Competing at 9,200 lbs, the SF Tractor relies on a single turbocharger and 640 cubic inches to power down the pulling surface. Known throughout the country as one of the largest classes in pulling, the Super Farm Tractors is most typically the closest class from the first place finisher to the tenth position!
Unlimited Super Stock (USS) is a class that generates more power than any other “stock” division. From their tube frame component chassis to their highly modified engine, these aren’t your granddad’s John Deere, Case-IH, or other brand models found in agriculture – hardly! These machines can create in excess of 5,000 horsepower weighing 6,200 pounds. Most of the engines have been modified to run on methanol fuel, although rarely fans will see a diesel-fueled Super Stock joining in the fray. Unlike all other forms of stock classes, the alcohol tractors do not blow plumes of black smoke. With methanol pumping through these engines, the USS class has become known for their ground-pounding power and amazing wheel speed. Keeping these bad boys between the lines and settled down is a daunting task for the driver, but the fans can’t get enough of the awesome power coming from these machines.


The Modified Two-Wheel Drive Truck (2WD) class is another filled with colorful American-made truck body styles, equally dazzling paint schemes and some of the more popular personalities behind the wheels. Using supercharged and alcohol-injected drag racing-type engines, these trucks indeed awe the crowd with their power and on-track antics, with part of their weight transfer characteristics resulting in towering wheel-stands at various points along the track. Their machines can weigh no more than 6,200 lbs, and finding the desired balance in keeping them pointed straight is truly a challenge.
Modified 4WD Trucks (4WD) are perhaps the closest in appearance to what the average Pickup Truck on the street is. 4WD trucks utilize both rear and front wheels to pull. With no turbocharger, or supercharger to force air into the engine, a competitor in this division must rely on the engine itself to pump as much air as possible and that means that engine settings like the proper air/fuel ratio are more important than ever. While steering and throttle application requires a lot of “finesse”, another huge challenge is placing as much weight at the front as possible, which allows the front two wheels to pull and claw a pathway early on, before the increased weight of the sled puts the final emphasis on the remaining pair of spinning tires at the rear. They have a weight limit of 6,200 pounds.
Who doesn’t love a pickup truck that can throw diesel plumes like crazy? The Diesel 4×4 (D4x4) is one of the fastest growing classes. Fans will shout their loyalty to their brand of choice as these 8,000 lb pickups come out to shows in high quantities. Running a stock body and an OEM CHassis makes this class the easiest to relate to their farm and work vehicles sitting in the parking lot.
The Pro Stock 4×4 Truck (P4x4) class will blow you away! These 6,200 lb four-wheel drive trucks use sick superchargers to boost power and bring unpredictable pulling results!