GT3, GT4, GTE and LMGT3 explained: what the sportscar classes actually mean

Sportscar racing has more class names than it has classes. GT3, GT4, GTE, GTLM, GTD, GTD Pro, GTDX, LMGT3. Some of those are the same cars under different championship rules. Two of them no longer exist.

Here is what each one is.

GT3

The one that matters most. GT3 is an FIA-homologated category built from road-going supercars, running roughly 500 to 600 horsepower with ABS, traction control and carbon bodywork.

The important part is Balance of Performance. Cars from completely different layouts, a mid-engined V8, a front-engined V10, a flat-six, are adjusted with weight and power restrictions until they lap at similar speeds. That is what lets a Ferrari, a Porsche and a Ford share a class without one of them simply being better.

GT3 is now the global default. GT World Challenge America, British GT, DTM and most national GT championships all run it, and its cars form the basis of the GT classes in both major endurance championships.

GT4

The step below. GT4 cars are much closer to the road cars they come from: less aerodynamic development, less power, fewer electronics, considerably cheaper to run.

GT4 is where most amateur and semi-professional GT racing happens. GT4 America is the North American championship, and the class appears as a support category almost everywhere GT3 races. GT America and International GT both carry GT3 and GT4 entries.

If you are watching a multi-class GT race and one group of cars is visibly slower and looks more like something you could buy, that is GT4.

GTE, and why it is gone

GTE was the manufacturer-focused class: purpose-built race cars with far more development freedom than GT3, run by factory teams at enormous cost.

It was replaced. From 2024 the World Endurance Championship and Le Mans dropped GTE and moved their GT class to GT3-based machinery.

Our own index shows the handover. IMSA WeatherTech ran GTLM, the North American GTE equivalent, from 2016 through 2021 and then stopped. LMGT3 races first appear in 2024.

GTLM stopping in 2021 and LMGT3 starting in 2024 is the whole story of that transition, visible in the race count.

LMGT3

The GT class in the World Endurance Championship and at Le Mans since 2024. LMGT3 cars are GT3 cars with WEC-specific additions, including the illuminated number panels and leader lights that make classes readable at night.

A car built for LMGT3 is fundamentally a GT3 car. The championship rules around it differ, particularly on driver line-ups.

GTD and GTD Pro

IMSA's names for its GT3 classes.

GTD requires an amateur in the line-up, which is what makes it a Pro-Am class.

GTD Pro allows all-professional line-ups. It replaced GTLM in 2022, which is why our GTD Pro races start that year. Ferrari Challenge and Lamborghini Super Trofeo NA run their own single-marque equivalents alongside these.

Same cars in both. The difference is who is allowed to drive them, and that difference is large enough that we rate the two classes separately. Treating them as one field made GTD Pro look considerably stronger than it is.

IMSA added a third GT3 class, GTDX, in 2025.

Quick reference

The thing most guides skip

Class names describe rules, not speed. Two cars in the same class can be separated by a lot, and a car in a slower class with a professional line-up can beat a faster car with an amateur one.

This is why driver grading exists alongside the classes. Look at any GT World Challenge America entry list and the line-up rules are doing as much work as the Balance of Performance. A GT3 grid is balanced twice over: once by adjusting the cars, and once by controlling who can drive them. We wrote about the driver half of that in FIA driver categorisation explained.

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Class race counts computed from the RacerDB index. Class rules per the FIA and championship regulations.