One of the most recognizable features of a monster truck are its large tires. Monster trucks use tires originally created for agricultural equipment, modified for use on monster trucks, with some tires being specifically made for monster trucks. Standard modern monster truck tires are 66 inches tall and 43 inches wide.
With the growing popularity of mud bogging in the 1970's, there began a quest to find larger, more suitable tires for increasing a 4-wheel drive pickup truck's capabilities in the mud. Early on, 48 inch agricultural tires were the standard for the few monster trucks that did exist, such as Bigfoot and King Kong, specifically the iconic design of the Goodyear Super Terra Grip tires. These tires are also known as flotation tires, as they were originally designed so that their volume of air means the farming equipment that uses them can float slightly on wet, muddy fields instead of sinking into the mud and getting stuck.
In 1979, a vehicle known as "Mud Rat" was seen at a mud bogging event sporting a set of 66x43-25 inch Super Terra Grip tires, which caught the attention of various monster truck owners, giving them the inspiration to put them on their trucks as well. On September 1st, 1982, Bigfoot 2 would make its first public appearance with a set of 66 inch Terra tires, leading others to follow suit.
One tire alone, without the rim, can weigh anywhere from 800-900lbs; when multiplied by four, tires take up about a third of the truck's average 10,000lb weight. A team can go through as many as eight tires in a single year. Tires can cost $2500-$7500 each.
Despite their size and rigidity, due to the weight of the trucks the tires tend to flex a considerable amount. This generally occurs only for a split second, but sometimes the tires flex so much that the rims of the wheels make contact with the ground. To combat this, some drivers over-inflate the tires. This, however, raises the risk of tire blowouts.
One of the most distinct elements of a monster truck tire is the tread pattern of the tire. The agricultural tires that are the basis of monster truck tires usually have a simple tread of deep, sharp V-shaped or alternating stripes (depending on manufacturer) intended to provide grip in mud or loose soil without getting clogged with earth.
For monster truck use, this tread is modified by the team, usually by removal of some rubber through "cutting". Tire cutting is done though for more than just stylistic reasons, though, as different tire treads result in different performance. Tire cutting is also done to accommodate the driver's driving skills and the conditions in which the truck will be driven. The most common modification made is to reduce the overall tread depth, which reduces weight and increases flexibility, and to round the edge of the tread near the sidewall, which makes it easier for drivers to upright the truck if they land on the edge of the tire after a jump. Cutting each individual tire takes approximately 50 consecutive hours.
A majority of trucks have their tires mounted with the tire stripes pointing downwards. On occasion, trucks may run some, or all tires facing the opposite direction. This may be for stylistic reasons, or because the backwards facing tire is an opposite side replacement for a flat.
Monster truck tires are so large with their regular tires that they cannot fit into their transportation trailers. Because of this, the tires have to be mounted on and unmounted back off after every show weekend. Much smaller tires, taken from the ones used for irrigation equipment, are put onto the truck so it can be driven back into its trailer. These are used as they can match the hubs on the large tires..
Trailers have doors on the side that allow for the tires to go in and out easily when loading and unloading the truck.
The most notable non-standard tire used are ten-foot tires: First used for monster trucks on Bigfoot 5, these were originally created for use on a US Army "land train" in Alaska.
"Plain" tires are used mostly on ride trucks, and rarely on race trucks. The most notable exception was when Predator trucks exclusively used these tires in the early 2000's.
- BKT: BKT tires are run on all Monster Jam trucks since 2014 and is a major sponsor of the league. However, the move was heavily criticized by most fans during the first wave of the tires due to their thinner surface, lighter weight, and smoother cut, leading trucks to tend to blow its tires easily. BKT, who were new to monster trucks and never made tires for them before, strengthened and otherwise readjusted their tires to address the issues. Despite the changes and fixes, false rumors still circulate about the strength of the tires, and them being the cause of the decrease of crush cars (which was actually due to safety, and that most of the drivers ended up preferring the dirt created obstacles.)
- Firestone: A well known leading brand for monster truck tires is Firestone. It has a thicker cut which gives the truck more grip. From the early years of monster trucks, this brand have been used on most trucks outside Monster Jam. Bigfoot is known for having Firestone as a longtime sponsor, which even led to the creation of the Firestone Bigfoot monster truck.
- Goodyear: Another pioneer of monster truck tires is Goodyear. It was used in the early years of monster trucks and set the standards for many other brands.
- Marcher: A Chinese tire manufacturer, Marcher's range includes the QZ-702A and the QZ-702C, both 66" tires that are primarily designed for agricultural equipment but can also be used on monster trucks. Furthermore, Marcher produces the W-10A, which is a purpose-built monster truck tire. Wrecking Machine originally used these before switching to BKT.
- Ukraine: Ukraine Tires is one of the widely used monster truck tires in the business. Before the switch to BKT, most Monster Jam trucks used this kind of tire. Due to its finer cut and sharper corners, the Ukraine Tires are more durable and can withstand a large amount of abuse.
Trucks can often times lose tires from hard hits, causing them to roll away over great distances. The large weight of the tire can pose a safety risk when this happens. In 2012, when Marc McDonald, driving El Toro Loco in Arlington Texas, lost a tire during freestyle, it bounced several times, initially in excess of 20+ feet high. It collided with the Fiesta truck and landed wedged between the truck and the wall; thankfully, nobody was hit by the tire. That was the second time that night a truck had lost a tire, a nearly similar incident happened with Bounty Hunter during that same show.
In 2015, Raging Bull lost a tire at a monster truck show and caused it to roll into a fence next to a section of spectators. The tire crashed into the fence and injured nine spectators on the other side; thankfully, nobody was killed.
In 1998, a fire burned down a garage resulting in Demon, Kimosabe, Showtime, and the Weapon 1 Ride Trucks all being destroyed. The fire was caused by tires that caught fire due to a faulty battery on a "power wheels" vehicle. The tires expanded from the heat until they violently burst, resulting in further explosions and causing the destruction of the garage.