Updated: January 12th, 2023.
The FIA, commonly with the ACO and IMSA added a few lines to the technical regulations of the fastest categories. Yet, many people still don’t know the difference between the Le Mans Hypercar and Le Mans Daytona hybrid (LMDh) classes. Note, this article will be constantly updated.
Text: Luca W. © Images: FIA, ACO, IMSA, Peugeot, Porsche, Ferrari ©
Both categories have many things in common, and the objective is to favor the convergence between those two. Why? Because both will be racing in 2022 at the 24h of Le Mans and even in the same category. The problem is, there are many questions around those new classes. What are the differences? Which teams are in? What are the technical specs?
Here is an infographic that summarizes everything you need to know on those classes.
If you’re more into details, click to jump on a specific topic in the table of contents below.
1. What do LMDh and LMH stand for?
LMDh means Le Mans Daytona Hybrid and LMH stands for Le Mans Hypercar. Both will run in the Hypercar class in the FIA World Endurance Championship.
2. Will LMDh and LMH race at Le Mans?
LMH cars are going to race at Le Mans. However, LMDh constructors still have to choose whether they will compete at the 24h of Le Mans, or not. This sub-category is implied for both WEC and IMSA championships, and some teams are looking at the IMSA rather than the WEC championship.
3. Budget
Both categories have many shared aspects that we will detail further in this article.
The key distinctness is the cost cap. ACO stated running 2 hypercars will cost 80% less than LMP1 cars. LMDh is an answer from the ACO and IMSA collaboration to teams for cost issues, mainly due to the COVID-19 pandemic but also the development costs that private teams and even constructors can no longer assume. To summarize, it is the DPi 2.0 racing class.
For the record, a LMDh car cost is capped to €1’000’000 (without the ICE – Internal Combustion Engine), while there is no budget limit statement for the LMH category. The final purpose of creating those new categories is to set a BoP (Balance Of Performance). So, both can compete against each other in the FIA World Endurance Championship (FIA WEC) and LMDh can also race in the IMSA Championship.
4. Powertrain
For both categories, constructors (or teams) are free to choose the ICE architecture, capacity, and technology. However, LMDh internal combustion engine maximum power output is limited to 470 kW (640 hp) and LMH to 500 kW (671 hp). Combined to a hybrid system, the power output is pushed to 500 kW (671 hp) for both.
Tired to convert power units? Try out our live unit converter!
In the LMH class, Peugeot will use a 2.6-litre, turbocharged V6 engine (revealed) and Glickenhaus a turbocharged V8. Toyota, that introduced the GR010 Hybrid earlier in January, will use a 3.5-litre V6 twin-turbo engine, providing 671 hp to the rear wheels and combining with a 272hp motor generator unit. Obviously, there is a need for an electronic management of power delivery, as the combined power output should be 671 hp. The LMH hybrid system can deliver power to front and/or rear wheels, while LMDh hybrid system is only delivered to the front wheels.
Comparing it with the LMP1 class, there should be a 30% power drop.
5. Weight
Both categories’ cars should weight 1,030 kg, after FIA clarifications. To play with numbers, there should be a 15-20% weight increase, in comparison with the LMP1 cars.
6. Le Mans Hypercar and LMDh platform
The LMH platform is a prototype, derived (accordingly to car manufacturer wishes) from an existing, road legal hypercar (or supercar) or vice versa. Toyota, for instance, will market it (cancelled due to crashes), based on their LMH prototype. The LMDh platform (chassis) should be common to many teams, and exclusively supplied by Dallara, Oreca, Multimatic or Ligier. For the record, Audi and Porsche have partnered with Multimatic to design their platform. The spine (complete car without bodywork, engine, hybrid) is the same as the future LMP2 cars. For example, the wheelbase is common (3,150 mm) and both width and length under regulations (2,000 mm and 5,100 mm respectively).
7. Aerodynamics
LMDh bodywork and so, aerodynamics, are regulated (e.g., downforce/drag ratio 4:1). However, competitors can use an identified bodywork, following the brand identity. The — carbon fiber — bodywork regulations aim to come back to the 90s, with distinctive, identifiable and conventional cars (even if it’s yet not the case in 2021).
In the LMH category, the technical rules offer more liberty. Except for safety issues, aerodynamics, and bodywork rules are pretty open, even for the floor. As you can see on the Toyota GR010 (Toyota’s Hypercar), the body clearly reminds us of previous LMP1 prototypes.
Peugeot takes another approach on aerodynamics on its new 9×8 Hypercar. Looking at the rear, there’s no wing. For the moment. Regulations only allow one adjustable aerodynamic element and Peugeot, through simulations, turned their heads to another one. The 2022 season will tell more about it because it is very singular for a race car to have no rear wing.
8. Hybrid system
On one hand, the LMDh category hybrid system is communal, can regenerate up to 200 kW and deliver 50 kW to the rear axle. Bosch develops the motor, while Williams Engineering supplies power management and energy storage. X-trac completes the gearing. The hybrid system should not be used at slow speeds and accelerations (at least 120 kph).
On the other hand, the LMH hybrid system architecture is not mandatory. However, considering modern hypercars, it should be almost identical to the road legal sports car (if there is one) and can deliver up to 200 kW to one end. Meaning that LMH cars can be either 4-wheel drive or exclusively rear-wheel drive. You guessed it: the gearbox development is up to the team. This might give a performance advantage to LMH cars. However, the hybrid system can not be used under 120 kph (75 mph).
9. When will the category start?
The Le Mans Hypercar series started in the 2021 season, while LMDh cars should enter the competition in 2023.
10. Le Mans Hypercar and LMDh entries
Here is a small table that recaps all entries in each category:
| LMH | LMDh |
| Toyota (2021) | Porsche (2023) with Team Penske, JOTA (WEC and IMSA) |
| Glickenhaus (2021) | Acura (2023) |
| Alpine (2021 – LMP1 conversion) | BMW Motorsport (2023 – IMSA / 2024 Le Mans) |
| Vanwall (2023) | Cadillac (2023) |
| Peugeot (2022) – 24h of Le Mans in 2023 | Alpine (2024) |
| Ferrari (2023) with AF Corse | Lamborghini (2024 – WEC and IMSA) |
| Bugatti (rumour) | McLaren (likely) |
| Ford (rumour) | |
| Phoenix Racing (rumour) | |
| Proton Competition with Porsche (likely) | |
| WRT (rumour) |
Both categories will have a unique tire supplier (Michelin).
11. The FIA April 2021 technical regulations issue
If you are curious enough to go deep into the detailed technical rules, feel free to download the FIA issue of April 2021.
12. Are LMH and LMDh faster than LMP1 cars?
No, they are slower. ACO estimated lap times in a 3:20 range on the 24h Le Mans track. After the 2021 24h of Le Mans, the conclusion is clear: LMH cars are 8.643 seconds slower than 2020 LMP1 cars in qualifying.
This is mainly due to fixed weight (1,030 kg) and power output (671 hp). In comparison, the new Toyota GR 010 (LMH) is 152 kg (17%) heavier and has 32% less power than the 2019 Toyota TS050 Hybrid (LMP1). In the simple power/weight ratio, physics tell these new racing cars are slower.
However, collected data shows that the gap isn’t that big: just under 2 seconds on a shorter track (e.g., 6 Hours of Spa Race). Looking at the chart below, here is a lap time comparison between categories at the 2021 24h of Le Mans race.
13. In a nutshell
What can we expect from these new regulations? Actually, a lot of things. Firstly, we assume there will be quite a show because both categories are very close in terms of performance. Secondly, at the moment, there are many teams that approved the program by joining in: 12 already! Gazing at the constructors’ enthusiasm may give us a hint that there will be more of them in the future. Also, this program allows to drastically reduce costs, which allows smaller teams to join in and fight with the big guys. And last but not least, the showcase concept has never been that truthful, because some road technologies will fit the cars and vice versa.
To see the first battles between those new racing cars, for which we have high hopes, we still have to wait a few months.
