Toyota Motor Corporation will enter the ENEOS Super Taikyu Series 2025 Empowered by BRIDGESTONE Round 3 NAPAC Fuji 24 Hours Race, to be held from 30 May to 1 June, with the #28 TGRR GR86 Future FR Concept running on low-carbon gasoline (E20) and the #32 TGRR GR Corolla H2 Concept running on liquid hydrogen.

The #28 GR86 will be fueled with low-carbon gasoline (E20) manufactured by ENEOS Corporation (ENEOS) in the harsh environment of endurance racing and generate technical feedback.

ENEOS and car manufacturers sharing the same vision will take on the all-Japan co-challenge of refining fuel to help accelerate its widespread adoption for the goal of achieving a carbon-neutral society.

In 2023, the liquid hydrogen-powered GR Corolla became the first vehicle in the world to use liquid hydrogen as fuel in a direct-injection engine*1. As part of the first-half stage of development, Toyota has been refining the durability of liquid hydrogen pumps as well as technologies such as oval tanks that extend cruising range.

In last year’s Fuji 24 Hours Race, while Toyota’s team met its goal of running 30 consecutive laps on a single hydrogen refill, issues with the electrical system forced repeated pit stops, preventing the car from running for a sufficient amount of time.

The goal for this year’s race is to run for the entire 24 hours with a more reliable vehicle and liquid hydrogen system and to utilize the data obtained for future development, with the goal of making ever-better motorsports-bred cars.

Low-carbon gasoline (E20) is a low-carbon fuel made by blending approximately 20% bioethanol with gasoline. Toyota will evaluate various types of low-carbon gasoline (E20) in the Super Taikyu Series and provide feedback from a technical perspective to build a knowledge base for supplying low-carbon gasoline with a maximum bioethanol concentration of 20%.

Further evolution of the liquid hydrogen-powered GR Corolla. As the culmination of the first-half stage of the liquid hydrogen-powered GR Corolla, Toyota has made the following technical improvements for this race based on the results of last year’s race.

Taking on the challenge of utilizing a hydrogen engine combustion switching technology that balances high output and fuel efficiency. Starting with this race, Toyota will take on the challenge of utilizing technology that automatically switches between stoichiometric combustion, which delivers high output, and lean combustion, which enables fuel-efficient driving, in response to the driver’s output requirements (accelerator operation).

Until now, Toyota has continued to improve stoichiometric combustion to achieve high output equivalent to that of gasoline.

From this race onwards, Toyota will take on the challenge of utilizing technology that smoothly switches to lean combustion when high output is not required with a view to applying it to the development of future production vehicles.

Developing a new filling valve that improves hydrogen filling speed and safety while making the vehicle compact and lightweight. Toyota has adopted a new structure for the filling valve used during hydrogen supply.

To date, valve opening and closing have been operated by an external actuator. However, in addition to limitations in expanding the flow path area during hydrogen supply, there have been challenges with improving airtightness in a -253 °C environment.

For this race, adopting a new internal piston structure has enabled an increase in flow path area, improving filling speed by approximately 30%. The new structure also eliminates the need for an external actuator, reducing weight by 2 kg. Furthermore, eliminating external opening and closing processes has improved airtightness and reduced the risk of hydrogen leakage.

Reducing vehicle weight through partial use of aluminum wiring for wire harnesses. A portion of the wire harnesses―bundles of wires distributed throughout the vehicle for power supply and signal transmission―has been changed from copper to aluminum wiring. Until now, corrosion caused by water exposure at terminal connections and other areas has posed a challenge in using aluminum wiring for wire harnesses.

For this race, adopting a sealed-structure terminal (Alpha terminal) using fiber laser welding technology developed by Furukawa Electric Co., Ltd. has made it possible to prevent water infiltration without compromising mass-producibility and cost competitiveness, thereby preventing corrosion, which had been an issue.

This change has also resulted in an 18% weight reduction compared to conventional wire harnesses.