The ACF imposed a maximum weight limit—excluding tools, upholstery, wings, lights and light fittings—of , with an additional allowed for a magneto or dynamo to be used for ignition. Regulations limited fuel consumption to . Every team opted for a magneto system; all used a low-tension system except Clément-Bayard, Panhard, Hotchkiss, Gobron-Brillié, and Renault, which used high-tension. Mercedes, Brasier, Clément-Bayard, FIAT and Gobron-Brillié used a chain drive system for transmission; the rest used drive shafts. All entries were fitted with four-cylinder engines; engine displacement ranged from for the Grégoire to for the Panhard. Exhaust pipes were directed upwards to limit the dust kicked up off the roads. Teams were allowed to change drivers and equipment, but only at the end of the first day's running, not while the race was in progress.