American Iron is a group of North American road racing classes sanctioned by the National Auto Sport Association (NASA).
American Iron racing features domestic muscle or pony cars such as Ford Mustang, Chevrolet Camaro, and Pontiac Firebird in four classes, Camaro Mustang Challenge (CMC & CMC-II), American Iron (AI), and American Iron Extreme (AIX). It has large, closely contested fields of V8 powered cars.
The different classes reflect various levels of permitted modifications, from the near showroom stock entry level Camaro Mustang Challenge (CMC) class, through to the "almost anything goes" American Iron Extreme (AIX) class at the opposite end of the scale. CMC, CMC-II, and AI classes have a power to weight limitation, while AIX is unrestricted.
American Iron races are run at all NASA regional events, as well as the annual National Championships currently held each year in September at Miller Motorsports Park in Tooele, Utah. Previously, the championships were held at Mid-Ohio Sports Car Course.