These classes are intended for everyday, street-legal vehicles with minimal to no changes. They require stock drivetrains and ensure all basic safety equipment (like seatbelts and brakes) are intact and functional.
This class allows for more extensive modifications than the stock class. Rules might permit larger tires (e.g. up to 36 inches), engine modifications, and altered suspension systems.
This is the most lenient class, allowing for significant vehicle rules, often focusing solely on safety requirements rather than vehicle specs, and larger tires (e.g. 37 inches and larger) are permitted.