On the first day of the Official Test at Okayama International Circuit, during the midday interval on March 6th, GTA President & CEO Masaki Bandoh held a press briefing to explain the regulation changes for the 2026 season.
*For details on the 2026 season regulation changes, please read this article. [2026 SUPER GT Regulation Updates] GT500 cars limited to 1 engine per season in a bid for greater durability. Success refueling restrictor introduced to the GT500 class also.
This season marks the end of the development freeze for GT500 class vehicles, allowing each manufacturer to make significant changes to vehicle aerodynamics and other areas. Manufacturers and teams have already been actively conducting tests. The GT500 class vehicles for this season will be limited to using only one engine throughout the season. Regarding this, President & CEO Bandoh stated, “The currently used NRE (Nippon Race Engine) is an excellent engine. While we need to consider future engines that address environmental issues, the direction for such development is not yet clear, and it would be costly. Considering these factors, we have decided to carefully use the NRE engine. After discussions with the three manufacturers, we have promoted reducing the number of engines to lower development and operational costs while improving durability. This year, the race and test distances are similar to last season, but we will compete with one engine to reduce costs.” He also revealed that next season they are considering extending the race distance with the same single engine.
Furthermore, the Success weight system in the GT500 class has been revised this season to use both a fuel flow restrictor and a refueling flow restrictor. President & CEO Bandoh explained, “This method was adopted to successfully implement the one-engine rule. When competing with one engine for the entire season, considering durability, it is better to restrict fuel flow. Reducing the initial value means we need a restrictor with a smaller diameter than the one used last year. Also, restricting fuel flow reduces power and speed, but looking at corner exits, reducing the speed difference with the GT300 class any further would be dangerous. For these two reasons, we decided to use the refueling flow restrictor in combination. This allows us to apply success handicaps without reducing the speed of GT500 cars on the course.”
Additionally, the GT500 class, which has used carbon-neutral fuel from Haltmann Carless, will switch this season to domestically produced E10 fuel developed by ENEOS. However, the adoption of this fuel in the GT300 class is still under consideration, as compatibility tests need to be conducted for all GT300 vehicles. This season, the GT300 class will use unleaded high-octane gasoline sold at circuit gas stations.
Finally, progress on the one-make tire system starting next season was reported. The bidding process has ended, and negotiations are underway with the tire manufacturer holding the priority negotiation rights. From the fourth round at Fuji in August, tests are planned at each circuit on the following Mondays. President & CEO Bandoh said, “The one-make tire system started with the goal of reducing the operational burden on teams. While it will reduce operational burdens, using the same tires means drivers and engineers will need to demonstrate greater skill. It will make the competition more severe.” They aim to announce the tire manufacturer as early as the Official Test at Fuji.
