There are many different types of kits for all-terrain vehicles (ATVs) that can improve performance and handling or add different functionality. Performance-enhancing ATV kits typically include mufflers and air filters that can result in an increase of horsepower. Certain ATVs can also accept engine kits, which are larger displacement engines that simply bolt up in place of the factory unit. Some modifications can also improve trail performance, such as an ATV lift kit that allows for the installation of bigger tires. Other kits are designed to add extra storage capacity or even allow an ATV to maneuver through the snow.
Performance enhancing ATV kits typically include an air filter and muffler that can be bolted on in place of the original equipment. The air filters included with these ATV kits are usually designed to allow a higher volume of air flow, which can reduce the effort needed to aspirate the engine. Combined with a muffler that allows a less restricted flow of exhaust, this can result in a higher horsepower rating from the engine. Some of these ATV kits can result in a vehicle that cannot be legally operated though, especially if the performance muffler lacks a spark arrestor. This makes it important to verify that the parts included with a performance ATV kit are approved by the appropriate agency, such as the United States Forestry Service (USFS).
An ATV lift kit can also improve performance, specifically on rough terrain. These kits are intended to raise the suspension of an ATV, creating more ground clearance and space for bigger tires. If larger tires are installed, they can create even more ground clearance. When traveling over very rough terrain, this increased ground clearance can help keep an ATV from bottoming out, being damaged or even getting stuck. These kits can sometimes be installed by the owner, though it is often necessary to hire an ATV mechanic to do the job.
ATV luggage kits are another type of accessory that serve a completely different purpose. These kits typically consist of a variety of saddle bags, fender bags and cargo nets that can greatly increase the amount of gear an ATV can haul. Some ATV luggage kits even include specialized pieces such as rifle cases, which can come in handy when using these vehicles as hunting rigs.
Track kits are one of the most drastic modifications that can be made to an ATV. These ATV kits replace the wheels with tracks, allowing much easier movement over snow and ice. Four-wheel drive track kits replace all the wheels with tracks, while other versions have skis that can be installed in place of the front wheels. Some ATV track kits are also designed for dual usage, such as both snow and mud.