The GT classes of sports car racing offer some of the most exciting and diverse forms of Motorsport, with many road-based cars of different specifications often sharing the track at the same time. This leads to great racing, but understanding the differences between them can be difficult. Here I will attempt to differentiate between the GT classes, so that you may enjoy the sport more fully.
For the sake of clarity, we will stick to classes that currently exist. Attempting to research/explain GT classes before this point will get fairly confusing. I know this because I initially tried, and I got a headache.
GTE
GTE is currently the highest level of GT racing, and is further split into two levels, Pro and Am. GTE-Pro is largely defined by manufacturers and factory backed teams, and GTE-Am is for privateers. GTE-Am cars are required to be at least one year old or made to the previous year's specification. This category was called GT2 before 2011, and is called GTLM in the United SportsCar Championship.
GTE cars must meet certain specifications designed to keep them closely related to the road cars they are based on. This is known as homologation. In order for a car to qualify, a large manufacturer (like GM) must produce at least one road going version of the car per week, or one car a month for small manufacturers (like Ferrari). These cars must also be available for sale, with an official launch campaign for the road car and network through which the car can be sold. The cars must have only two doors, a two or 2+2 seating configuration, and have bona fide sporting ambitions. The car is not required to use the engine it is offered with (although it usually is), but it is required to be a production engine used in a road car. Carbon fiber, titanium and magnesium cannot be used outside of parts like spoilers and wheels, unless the road car has a carbon cockpit. All cars are rear-wheel-drive, and engine-based traction control is allowed. Also, in an interesting nod to the Le Mans era of old, every GTE car is required to have 150 cubic decimeters of luggage space.
Cars Currently Racing in GTE:
Aston Martin Vantage GTE
BMW Z4 GTE
Chevrolet Corvette C7.R
Ferrari 458 Italia GT2
Porsche 911 GT3 RSR
SRT Viper GTS-R
Cars Homologated for GTE, but not Currently Racing:
BMW M3 GT2
Chevrolet Corvette C6.R
Ferrari F430 GT2
Ford GT GT2
Jaguar XKR GT2
Lamborghini Gallardo LP560-4 GT
Lotus Evora GTE
Panoz Esperante GT-LM
Spyker C8 GT2R
These Series Currently Feature the GTE Class:
FIA World Endurance Championship
United SportsCar Championship
European Le Mans Series
Asian Le Mans Series
International GT Open
GT3
GT3 was initially launched in 2005 by the FIA, and was designed to fit under the GT2 specification. This category was designed to be much simpler and easier to drive than the GT1 and GT2 classes, so that amateurs and younger drivers could work their way up into higher levels of GT racing. This class has become the most popular class of GT racing in the world as it is present in most regional racing series all over the globe. In the United SportsCar Championship, GT3 cars are run in the GTD class with a different spec- rear wing.
GT3 cars have no limit on engine sizes and configurations, chassis construction, or layout, but they must be based on road cars that are in mass production, and a large variety of cars have been homologated. Occasionally you will see privateers run older GT3 cars, even if they are not in production anymore.
These cars have all been homologated for use in GT3, in alphabetical order. Some are no longer in use, but are still technically legal for use in GT3 races, even if they are not necessarily competitive. Those that have had their homologation expired are noted as such.
Cars Currently Homologated for GT3:
Ascari KZ1-R GT3
Aston Martin DBRS9
Aston Martin V12 Vantage GT3
Audi R8 LMS (Including R8 LMS Ultra)
Bentley Continental GT3
BMW Alpina B6 GT3
BMW Z4 GT3
Chevrolet Camaro GT3
Corvette Callaway Z06.R GT3
Corvette Z06.R GT3
Dodge Viper Competition Coupe
Dodge Viper Competition Coupe Series 2
Ferrari 430 GT3
Ferrari 430 Scuderia GT3
Ferrari 458 Italia GT3
Ford GT GT3
Ford Mustang FR500C GT
Lamborghini Gallardo LP600 GT3
Lamborghini Gallardo LP600+ GT3
Lotus Exige GT3
Maserati Coupe Grand Sportif Light
Maserati GranTurismo MC GT3
McLaren MP4-12C GT3
Mercedes SLS AMG GT3
Morgan Aero 8 GT3
Morgan Aero Super Sport
Nissan GT-R Nismo GT3
Porsche 911 997 GT3 Cup (2006 model only)
Porsche 911 GT3 Cup S
Porsche 911 GT3 R
SRT Viper GT3-R
Venturi Atlantique GT3 Heritage
Cars with Expired Homologation (No longer meet specification):
Ford Mustang VDS GT3 (Homologation Expired)
Jaguar XKR GT3 (Homologation Expired)
Jaguar XKR-S GT3 (Homologation Expired)
These Series Currently Feature the GT3 Class:
24 Hour Series
ADAC GT Masters
Asian Le Mans Series
Australian GT Championship
Belgian GT Championship
Blancpain Endurance Series
Brazilian GT Championship
British GT Championship
European Le Mans Series
FFSA GT Championship
FIA GT Series (Formerly Blancpain Sprint Series)
GT Asia Series
International GT Open
Italian GT Championship
Portuguese GT Championship
Spanish GT Championship
Superstars International Series (Formerly GTSprint International series)
Super Taikyu Series
Veranstaltergemeinschaft Langstreckenpokal Nürburgring (More popularly known as VLN)
These Series allow GT3 cars to compete against cars of different specifications:
Dutch Supercar Challenge (In the GT Class)
Pirelli World Challenge (Featured in the GT Class)
United SportsCar Championship (Featured in GTD alongside the Porsche 911 GT America)
Super GT (Featured in the GT300 category only)
GT4
The GT4 class was created to support the GT3 class with a true low tech amateur sports car series. The GT4 class consists of cars that are much closer to the road cars they are based on over than the other classes featured here. GT4 cars are often referred to as "Track Day" cars, as they are at price points that make them very accessible to gentleman drivers who want racing experience. The GT4 class is often seen accompanying GT3 classes in series around the globe. You'll also see GT4 class cars compete in single make series.
Cars are adjusted to have an almost identical performance level so that driver skill is highlighted, and once a car has been homologated it cannot be modified. This prevents a war of developmental cost increases, allowing the series to keep it a true amateur series.
Cars Currently Racing in GT4:
Aston Martin Vantage N24
Aston Martin Vantage GT4
BMW M3 GT4
BMW Z4
Corvette C6
Chevrolet Camaro
Ford Mustang FR500 GT4
Ginetta G50 GT4
Maserati Gran Turismo MC
Maserati Trofeo
Mazda MX5
Nissan 350Z
Nissan 370Z
Porsche 997 GT4
Porsche Cayman
Lotus Evora
These Series Currently Feature the GT4 Class:
24H Series
Blancpain Endurance Series
FIA GT4 European Series
Many Regional GT Championships
These Series allow GT4 cars to compete against cars of different specifications:
Pirelli World Challenge (Featured in the GTS Class
Continental Tire Sports Car Challenge (Featured in the GS Class)
There are many more racing series that use the GT4 class or feature cars built to this spec, so if you know of any more, let me know.
I hope that this helps you understand the current world of GT racing a bit more. Sometime in the future, I'll write a post about how GT racing got to this point, but this is how it exists now.
Photo Credits: IMSA, FIA WEC Website, Nurburgring.de, SRO Motorsports Group
I love racing and cars. I talk about that a lot on Twitter. Feel free to follow me at @willkinton247. If you want me to look into a particular series or topic, or have any feedback, let me know!
A Guide through the Confusing World of GT Classes