The classes
Four classes share the track. GTP heads the field — hybrid prototypes from Porsche, Cadillac, BMW, Acura and Aston Martin fighting for overall wins. LMP2 runs identical-spec prototypes with Gibson V8 power, a pro-am class where the gentleman drivers matter as much as the pros. GTD Pro and GTD use exactly the same GT3 machinery and differ only in who drives: GTD Pro takes all-professional crews, while GTD is pro-am, built around at least one Silver- or Bronze-rated driver. Same cars, two championships — read the entry list, not the bodywork.
The races
Eleven rounds mix sprints and enduros. The Rolex 24 at Daytona opens the year, Sebring runs twelve hours, Watkins Glen and Road America six apiece, and the ten-hour Petit Le Mans closes the season. The rest are sprints, mostly two hours forty, plus the short street fight at Long Beach. Not every class appears everywhere — Long Beach takes only GTP and GTD, Detroit GTP and GTD Pro, VIR the GT classes alone. Sprints are two-driver races; the enduros add a third (and at Daytona often a fourth) with minimum drive-time requirements policing the share of work.
Points
Deep scale, every finisher scores: a race win pays 350, second 320, third 300, sliding all the way down to 10 for 30th in class. Qualifying pays a tenth of that — 35 for class pole, 32 for second, and so on. The five long races also feed the Michelin Endurance Cup, scored separately on a 5-4-3-2 scale at checkpoints through each race: at Daytona the clock pays at six, twelve and eighteen hours plus the finish, at Sebring and Petit Le Mans at four and eight hours plus the finish, at the six-hour races at three hours and the flag.
The championships
GTP, GTD Pro and GTD each crown drivers, teams and manufacturers; LMP2, with its spec engine, awards drivers' and teams' titles. In the manufacturers' standings only each marque's best-finishing car counts, with everyone else moving up the order. The Michelin Endurance Cup hands out its own drivers', teams' and manufacturers' trophies across the five enduros — a championship within the championship, and a badge of honour in its own right.