The Toyota GR Yaris H2 is a hydrogen-fuelled, combustion-engined concept version of the brand's acclaimed four-wheel-drive hot hatchback.
It has been shown at Toyota's annual Kenshiki forum, during which the Japanese manufacturer heavily reinforced its commitment to hydrogen powertrain development as an alternative to all-out electrification.
Toyota has been testing hydrogen-combustion technology for several months now, using a lightly modified Corolla touring car – which uses a hydrogen-fuelled version of the GR Yaris's 1.6-litre turbo three-pot – in Japan's Super Taikyu race series.
Hydrogen-combustion technology, Toyota says, allows cars to become zero-emission relatively affordably as it allows manufacturers to exploit "existing internal combustion engine know-how and manufacturing investment".
Using this technology, Toyota's Europe CEO Matt Harrison said, would allow Toyota to "deliver almost zero tailpipe emissions without electrification, but it does so whilst retaining the things which fans love most about race cars – the speed and the noise."
"Music to the ears," he said, "especially to those of a petrolhead."
The GR Yaris H2 uses the same unit as the Corolla racer, with minimal modifications from standard, and has the same refuelling hardware as the brand's Mirai production car.
The subtle mechanical modifications are limited to strengthening the block (as hydrogen explodes more violently than petrol), new valve seats and an upgraded injection system. Powertrain boss Thiebauld Paquet estimated that it would achieve “similar efficiencies” to its unmodified petrol counterpart, but performance details remain under wraps.
Speaking after the concept’s reveal, Paquet told Autocar: “When we started it, we created a bit of vibration and a bit of noise, so it was clear and apparent how it sounds. That was one of the things we wanted to demonstrate: compared to fuel cell technology, which is very quiet, you can still get this feeling from sport, where you can hear and feel the car.
“In the first instance, it’s a concept. The idea is to use sports to find out the difficulties and how we can accelerate, how we can quickly come to improvements in the technology.”
Toyota has not confirmed the production potential of the GR Yaris H2, but Harrison said this technology means zero-emission motoring "needn't be a distant future".
He said: "The uplifting message of the GR Yaris H2 is this: even in a zero-emissions future, we could still enjoy motoring thrills similar to those we enjoy today."