Production (EP, FP, GP, EP) Series produced cars, which are allowed a range of performance modifications while retaining their original design, structure and drive layout. There is no age limit, such as Showroom Stock, so Production includes many cars as old as 50 years and as new as current body styles. The four performance potential based classes include: E Production (EP), F Production (FP), G Production (GP) and H Production (HP).
EP is the fastest of the Production classes with HP running the slowest in the category. Several cars in the Production classes can be run in more than one class, just by changing the engine between races. The ease of engine changes allows many Production drivers to enter more than one class at the Runoffs each year. Cars included in Production classes come from a diverse group ranging from the MG Midget, Turner, Fiat X1/9, Alfa Romeo Spyder, Austin Healey Sprite, and Lotus Super 7 to the BMW 325, Mazda Miata, RX-7, Nissan 240, Honda Civic, Suzuki Swift GTI and Toyota MR-2.