The new LMDh regulations at a glance

A WEC race in the United States
A WEC race in the United States

From 2022 on there will be prototypes based on LMDh regulations besides the hypercars. Read on to find out more about this new category.

The FIA World Endurance Championship will provide the opportunity for cars from two fundamentally different categories to compete in the top class of global prototype racing for the first time. From 2022, Le Mans Hypercars will compete directly against cars from the LMDh class.

Cars built according to LMH regulations enjoy a relatively high level of freedom when it comes to design and shape, and can be customised to the manufacturer’s precise requirements. The LMDh regulations are the United States’ answer to the future of prototype racing under the banner of IMSA, and provides a much stricter framework when it comes to car development.

In LMDh, competitors much purchase a chassis from one of the four approved chassis builders – Dallara, Ligier, Multimatic or Oreca. They are then free to add bodywork and styling cues to add the personal touch of their particular brand to the car, but no chassis alterations are permitted.

Modifications to LMDh cars can include the headlights and brake lights, the front grille and side pods. In addition, the cars’ underbody may also be changed to a limited extent.

Limited development through the LMDh regulations

The restrictions on LMDh prototypes are the same in IMSA as they are in the WEC. The minimum weight is 1,030 kg and the drive train may not deliver more than 500 kW of power. The wheelbase is set at 3,150 mm, and maximum width and length at 2000 mm and 5100 mm respectively.

Under the hood, a spec hybrid unit is set to be used together with a petrol engine delivering at least 470 kW of power. The Bosch hybrid unit is limited to 50 kW and energy recovery of 200 kW. The transmission is manufactured by Xtrac and the hybrid battery by Williams Advanced Engineering.

Costs are subject to a strict cap in IMSA competition, as in the case of the LMH cars in the WEC. However, given that LMDh prototypes contain many more spec parts than the LMH machines, the cost cap for one car excluding the engine is significantly lower at € 1,000,000.

Where LMDh cars can be raced

The first LMDh prototypes should start racing in the IMSA sportscar series from 2022. The coronavirus pandemic may still result in the new regulations being postponed to 2023, but at the moment the ruleset is still on track for a 2022 launch.

The LMDh prototypes will be able to enter the IMSA sportscar championship and the WEC, and crucially will also be welcome at Le Mans. There are currently no plans to allow the WEC hypercars, such as the Toyota GR Super Sport, to compete in US endurance race such as the 12 Hours of Sebring and the Daytona 24 Hours.

In order to establish a level playing field for the different approaches, a balance of performance system will apply in the WEC and at Le Mans. This system is AI-driven and is based partly on the success handicap system currently used in the LMP1 class. The algorithm will apply changes to the cars prior to each race, resulting in dynamic BoP adjustments across the season.

The official presentation of the LMDh ruleset is available here. For more information on the new WEC hypercar class (LMH), is available in our LMH explainer