The regulations at the 24 Hours of Le Mans have been revised in order to cut the amount of fuel used during the race, according to the organizing group of Le Mans. The changes take effect two years from now. This past weekend, Audi got first and second place endurance race but even before this happened, the Automobile Club de l’Ouest (Le Mans’ organizing body) and the Federation Internationale de l’Automobile have announced the new rules that are meant to lessen how much fuel LMP1 racer use in the race. For the past several years, the ACO has been urging racers to improve their fuel economy by regulating factors like the number of cylinders used and the engine displacement. There was also a time when it limited the size of the fuel tanks on board. The rules on fuel tank sizes would still be in effect.
The gas-powered cars would switch from 75-liter tanks to 64.4-liter tanks and diesel-powered cars will go from 60-liter fuel cells to 53.3-liter ones. However, the other regulations were scrapped by the ACO. In the LMP1 category, the private racing teams could only use engines up to 5.5 liters. However, factory teams could use those with any type of cylinder, any kind of displacement, and any level of forced induction pressure. The restrictions on fuel injection pressure or air intakes were also dropped by the ACO. But what the ACO would be strictly regulating is the fuel economy. The majority of regulations with regards to hybrid systems were also removed.
Teams could use just up to two systems at a combined power of as high as 8 megajoules -- four times higher than before. The fuel economy will also be regulated depending on the hybrid systems’ combined output. The fuel economy rating of a manufacturer’s hybrid racer with a 2 MJ hybrid system uses up to 4.8 liters of gas or 3.93 liters of diesel per lap (a fuel economy rating of 6.68 mpg and 8.16 mpg, respectively). Meanwhile, an 8 MJ hybrid is restricted to 4.42 liters of gas or 3.56 liters of diesel per lap (7.25 mpg and 9.0 mpg, respectively). It’s likely that the current DeltaWing racecar (equivalent to an LMP2 car would use up much as 4.5 liters of gasoline every lap without any hybrid powertrain. It’s probably the most frugal of the cars shown this past weekend.