The American Le Mans Series used essentially the same rules as the 24 Hours of Le Mans. Like the 24 Hours of Le Mans, there were three primary classes, though there were two extra "Challenge classes" using standardized cars. Purpose-built race cars with closed fenders competed in the "Prototype" classes P1, P2, and PC (Prototype-Challenge) and modified production sports cars competed in the "Grand Touring" classes GT (GTE-Pro and GTE-Am combined, formerly GT2) along with GT-Challenge or GTC. The former GT1 category was abandoned after 2009 season. In 2012, the "Le Mans" (LM) was dropped from the names of the prototype categories.