What is the difference between GT3 and LMGT3 cars?

With Le Mans Ultimate set to release its first LMGT3 cars, we felt now was a great time to delve into the differences between GT3 and LMGT3 cars.

On the face of it, the cars are very similar: a BMW M4 GT3 is almost indistinguishable from its LMGT3 equivalent, for example. But here are subtle differences, the biggest of which is the Balance of Performance (BoP) calculation between the cars is handled by different authorities.

GT3 overview

For GT3, the world’s largest motorsport governing body, the Fédération Internationale de l’Automobile (FIA), and the SRO Group decide on variables to help keep cars competitive, although older GT3 models like the Nissan GT-R and Bentley Continental will not always receive performance hikes to allow them to compete with newer cars.

Championships to follow GT3 BoP calculations include every series operating under the SRO’s GT World Challenge banner, plus notable championships like the DTM and British GT Championship.

GT3 cars are based on mass-produced road-going supercars and sportscars with various engine configurations, albeit only from the manufacturer’s road car range. They must be rear-wheel drive and have comparable power-to-weight ratios.

GT3 cars have a lot of aerodynamic grip and generally have between 500-600bhp in power, weighing approximately 1200-1300kg. Vehicles can be purchased directly from manufacturers, costing around £500k each.

GT3 cars cater for amateur and professional drivers alike, with driving aids such as traction control (TC) and anti-lock brakes (ABS) implemented as standard. Most driver lineups consist of one professional driver (rated as Gold or Platinum) and one amateur driver (Bronze), although there are dual Silver lineups allowed in some championships too.

Road cars such as the McLaren 720S, Porsche 911 and Ferrari 296 GTB, among many others, all have GT3 racing car variants.

LMGT3 overview

Paraphrasing the FIA’s own regulatory documents, ‘vehicles eligible for the LMGT3 class must be a model constructed by an ACO-FIA WEC-recognised manufacturer that complies with GT3 technical regulations’. So, LMGT3 cars are very much GT3-derived.

Manufacturers are only allowed to enter two LMGT3 cars in WEC each, with entry priority given to marques also entered into the Hypercar class. 

LMGT3 cars adhere to the classic Pro-Am arrangement in GT3 racing with each two-driver team consisting of one bronze-level driver (Bronze is considered amateur level) and one Gold or Platinum professional. At least three drivers are required for the 24 Hours of Le Mans, with this extra driver required to be Silver or Bronze-rated.

LMU will feature all of the 2024 LMGT3 grid by the time its fourth DLC pack releases in Q1 2025; so that’s cars from Aston Martin, McLaren, Ford, Ferrari, Corvette, Porsche, Lexus (Toyota), Lamborghini and BMW.

For LMGT3, the FIA and ACO decide on each car’s BoP (they also decide on Hypercar and LMP2 category BoPs). The ACO is France’s biggest automotive group and the organiser of the 24 Hours of Le Mans (its role is similar to that of ADAC in Germany).

The mandated top speed of an LMGT3 car is 300 kph, with the ACO and FIA able to adjust BoP to maintain the competitiveness of the class, altering factors such as power, weight, energy allowed per stint, refuelling times and aero tweaks.

What are the key differences between LMGT3 and GT3 cars?

Although no firm power figures are publicly available for GT3 and LMGT3 cars, driver feedback suggests that LMGT3 cars have slightly less torque, power and aerodynamic grip than their GT3 equivalents, meaning you should expect LMGT3 cars to be slower than GT3s on the same circuit.

LMGT3 cars also have a ‘virtual energy tank’, much like hybrid-assisted Hypercars, but they are solely powered by internal combustion engines. LMGT3 cars’ virtual energy usage is monitored by a torque sensor attached to the drive shaft, and going over a car’s allotted energy in a stint will result in penalties.

LMGT3 cars also exclusively use Goodyear tyres and use their own identification and position lighting systems, with each class featuring slightly different aero packages.

TL;DR

Here are the key similarities and differences between GT3 and LMGT3 cars.

	GT3	LMGT3
Tyre warmers	Allowed	Not allowed
Minimum weight	1,200 Kg	1,200 Kg
BoP decided by	SRO and FIA	ACO and FIA
Tyre supplier	Pirelli/Michelin	Goodyear
Fuel tank capacity	120 litres	120 litres (uses virtual energy tank with energy usage monitored by a torque sensor)
Side classification LEDs	No	Yes

Featured image courtesy of 24hLeMans.com