GT300 Class

GT300 Class

Definition and Core Status
The GT300 class serves as the secondary category of the Japanese Super GT championship, forming a two-tier multi-class racing format alongside the premier GT500 class. The GT300 moniker originated from its initial design benchmark of approximately 300 hp; although current outputs far exceed this figure, the class designation has been retained. Unlike the GT500 class, which is contested exclusively by Japan's Big Three manufacturers—Toyota, Honda, and Nissan—GT300 boasts a far more diverse racing ecosystem. Competing machinery encompasses Japanese domestic GT300-spec cars, customer racing cars built to international FIA GT3 regulations, and GT300MC (Mother Chassis) racers, making it the category with the widest variety of machinery and the most fiercely contested grid in Super GT.

Class Structure and Vehicle Categories
The GT300 grid is divided into three distinct categories. The first consists of Japanese manufacturer GT300-spec cars, including the Toyota GR86 GT300, Toyota GR Supra GT300, Lexus LC500 GT, Lexus LC500h GT, Nissan Fairlady Z GT300, and Subaru BRZ GT300.The second category covers FIA GT3-spec machinery, featuring contenders such as the Mercedes-AMG GT3, Porsche 911 GT3 R EVO, BMW M4 GT3 EVO, Ferrari 296 GT3 EVO, Aston Martin Vantage GT3 EVO, Lamborghini Huracán GT3 EVO2, Nissan GT-R NISMO GT3, and Lexus RC F GT3.The third category comprises GT300MC-spec machinery, represented by the Toyota 86 MC, which is underpinned by the standardised Mother Chassis architecture.

Technical Specifications
Taking the Toyota GR86 as an example of a GT300-spec machine, it is built on the ZN8 GR86 platform, measuring 4,550 mm in overall length, 1,950 mm in overall width, and 1,100 mm in overall height, with a 2,650 mm wheelbase, a minimum weight of 1,250 kg, and is powered by a 2UR-G 5.4-litre naturally aspirated V8 engine.The Lexus LC500 GT similarly employs the 2UR-G 5.4-litre naturally aspirated V8 engine with a minimum weight of 1,250 kg, whereas the LC500h GT integrates an additional hybrid system, raising minimum weight to 1,300 kg.On the FIA GT3 front, the Mercedes-AMG GT3 is powered by a 6.2-litre naturally aspirated V8 engine with a minimum weight of 1,285 kg; the Porsche 911 GT3 R EVO is equipped with a 4.2-litre naturally aspirated flat-six engine with a minimum weight of 1,250 kg; and the Aston Martin Vantage GT3 EVO is powered by a 4.0-litre twin-turbocharged V8 engine with a minimum weight of 1,265 kg.

Balance of Performance (BoP) Mechanisms
The GT300 class relies on comprehensive Balance of Performance (BoP) measures to level the playing field across different vehicle concepts. BoP parameters for FIA GT3-spec cars are formulated in collaboration between the GTA and SRO, aligned with international GT3 competition standards.Meanwhile, BoP adjustments for domestic Japanese GT300-spec cars are regulated through variables including minimum weight, air restrictor sizing, refuelling flow restrictor diameter, and minimum ground clearance. Official data from the 2026 season opener at Okayama indicates that the Subaru BRZ and Nissan Fairlady Z run without air restrictors, whereas the Toyota GR86 and Lexus LC500 series are fitted with twin 30.27 mm restrictors.The Success Weight ballast system is also enforced in GT300, where front-running cars are assigned additional weight penalties.

2026 Season Competitive Landscape
A total of 29 cars are entered in the GT300 class for the 2026 season, significantly outnumbering the 14-car field in GT500.At the season-opening Okayama round, the No. 777 D'station Vantage GT3 (Tomonobu Fujii / Charlie Fagg) secured pole position and converted it into a 26-point haul in the race to lead the drivers' championship standings.The No. 2 HYPER WATER INGING GR86 GT (Yuui Tsutsumi / Kazuhisa Urabe) sits second on 20 points, while the No. 31 apr LC500h GT (Kazuto Kotaka / Miki Koyama) ranks third with 16 points.In the team standings, D'station Racing leads with 28 points, closely trailed by HYPER WATER Racing INGING on 23 points, with apr in third on 19 points.The dynamic of the GT300 class reflects an ongoing contest between international GT3 models and bespoke Japanese GT300-spec machinery, ensuring that no single model establishes the prolonged dominance seen in GT500.