Organisations and series
ACO (Automobile Club de l'Ouest)
The French club that created and still runs Le Mans, and co-organises the WEC with the FIA.
The Automobile Club de l'Ouest is the French automobile club that created the 24 Hours of Le Mans in 1923 and has run it ever since. It owns the race, the Circuit de la Sarthe's permanent facilities and the Le Mans rulebook lineage that terms like LMH, LMDh and LMP2 descend from.
The modern World Endurance Championship is a joint enterprise: the FIA sanctions it as a world championship while the ACO organises and promotes it, with Le Mans as its centrepiece. The ACO also licenses continental series such as the European Le Mans Series, which is why prototype racing worldwide follows one family of technical rules.
Part of the WEC Engine glossary. Questions with longer answers live in Answers.