Sportscars · Top-Class Regulations
LMDh vs LMH — The Two Hypercar Rulebooks
The fastest sportscars in the world are built to two different rulebooks — LMDh and LMH — that race for the same trophy. They look similar, they perform similarly, and they fill the same grid. Here's what actually differs, and why both exist.
What's the difference between LMDh and LMH?
Both are top-class hybrid prototypes that make up the WEC Hypercar class and the IMSA GTP class. The difference is how much of the car the manufacturer builds.
LMDh ("Le Mans Daytona h") uses a spec chassis from one of four approved constructors and a single common hybrid system — a cost-controlled formula. LMH ("Le Mans Hypercar") lets the manufacturer build its own chassis, which may be derived from a road-going hypercar, with a manufacturer hybrid on the front axle. Both are then capped to similar power and weight and balanced against each other.
LMDh vs LMH, side by side
| Aspect | LMDh | LMH |
|---|---|---|
| Chassis | A spec chassis from one of four approved constructors — Dallara, Ligier, Multimatic or Oreca. | The manufacturer’s own chassis, which may be derived from a road-going hypercar. |
| Hybrid system | A single common spec hybrid: a Bosch motor-generator, a Williams Advanced Engineering battery and an Xtrac gearbox (around 50 kW / 67 hp). | A manufacturer-developed hybrid on the front axle (up to 200 kW), which can drive the front wheels above a set speed. |
| Cost | Lower — shared spec parts (chassis, hybrid, electronics) were the whole point of the formula. | Higher — bespoke chassis and powertrain development. |
| Power & weight | Capped at roughly 500 kW (670 hp) combined and 1,030 kg minimum, then trimmed by BoP. | Same ceilings — about 500 kW (670 hp) and 1,030 kg minimum — then trimmed by BoP. |
| Where it races | WEC Hypercar and IMSA GTP — both championships, plus Le Mans. | WEC Hypercar and IMSA GTP too. Both rulesets are eligible in both series. |
Who runs which (2026)
Both groups race in the same WEC Hypercar and IMSA GTP fields.
LMDh
- Porsche963
- CadillacV-Series.R
- BMWM Hybrid V8
- AcuraARX-06
- LamborghiniSC63
- AlpineA424
- GenesisGMR-001
LMH
- ToyotaGR010 / TR010 Hybrid
- Ferrari499P
- Peugeot9X8
- Aston MartinValkyrie
So why do they race together?
Because the goal was one top class, not two. After the expensive LMP1 era emptied the grid, the ACO and FIA created LMH, and IMSA and the ACO jointly created the cheaper LMDh in 2020 — deliberately written so the two rulebooks would perform alike and could share a grid.
Both are eligible in both championships, equalised race-to-race by Balance of Performance, and they line up together at Le Mans. The formula worked: it brought Ferrari, Porsche, Cadillac, BMW, Toyota, Peugeot, Lamborghini, Alpine, Aston Martin and Genesis back to the front of sportscar racing.
LMDh vs LMH FAQ
What is the difference between LMDh and LMH?
Do LMDh and LMH race against each other?
Which manufacturers run LMDh and which run LMH?
Why was LMDh created?
Is a GTP car the same as a Hypercar?
More sportscar guides
- Multi-Class Racing ExplainedWhy a car can finish 30th overall and still win — GTP, LMP2, GTD and the per-class result
- Balance of PerformanceWhy one manufacturer gets ballast and another gets power — how BoP equalises the field
- FIA Driver CategoriesPlatinum, Gold, Silver, Bronze — and why a class can require an amateur in the car
- Sportscar ChampionshipsThe Michelin Endurance Cup, the layered IMSA titles, and WEC’s per-class crowns
- Le Mans hubWhere LMDh and LMH meet once a year
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