The inside story behind the wild hydrogen-powered Lexus buggy

Yamaha brought its vast experience of producing lightweight off-roaders, with Lexus adding hydrogen combustion technology and access to more sustainable materials.

The biggest change is to the YXZ1000R’s 998cc direct-injection inline three-cylinder engine. The original runs on petrol, but for the Lexus the Yamaha unit has been converted to run on compressed hydrogen fuel, using a direct-injection system taken from the H2-powered GR Yaris concept.

“It was hard work,” says Kato. “We had to change all the head areas and the injector to ensure it was suitable.”

The H2 engine has a max output of 80bhp, compared with 112bhp for the original, reflecting that it’s still a work in progress and the focus has been on developing the technology, not maximising performance.

It retains a powertrain that can be switched between 2WD and 4WD, and a five-speed sequential gearbox.

Top speed is 62mph – 31mph down on the original but still plenty, given this is an off-road buggy designed for dirt tracks.

That said, you won’t take it on particularly long dirt trails because its hydrogen fuel tank (from the Toyota Mirai) gives it a range of around 11 miles.

But the short range and relatively low-speed use case are what made the project appeal to Lexus. “The H2 GR Yaris race car is more about high engine performance, whereas this is more like regular use,” says Kato. “We can use this to check performance in the 1000-2000rpm range and aspects like usability.”

The revamped powertrain ups the weight from 690kg to 760kg, while tread has been increased by 100mm at the front and rear (to 1470mm and 1520mm respectively), to improve rollover performance on bumps and ride comfort. This is a premium Lexus, remember.

Ground clearance remains 330mm. The KYB shock absorbers have been retuned both to account for the extra weight and to use biodegradable oil that can be recycled and will minimise environmental damage should it leak on a trail.

That’s an example of why the ROV isn’t just a showcase for the firm’s hydrogen combustion powertrain: the reworked body features a raft of materials designed to reduce the environmental impact of its manufacturing and use.

The windscreen is made from bio-based polycarbonate and is claimed to use 80% less CO2 in production than a standard one.

The bumper and bonnet are made from material recycled from scrapped cars and blended with a bio-based resin, while plant-based biodegradable plastics are used for the fixture clips.

The seatbacks use recycled thermoplastic polyester and the body is covered in a film wrap – 9kg lighter than painting it and easier to repair when scratched.

And it will get scratched, because the ROV is intended for off-road use and, frankly, there aren’t many places it can’t go.

A short passenger ride on the Dreux circuit’s motocross course showed as much, with the suspension giving it a physics-defying ability to remain planted to the ground even on the steepest of yumps and bumps, while also allowing for fast, stable cornering on loose, rocky gravel.

It’s fun, then. But it’s also a sign of Toyota’s approach to development, working with partners to broaden its expertise. “Yamaha doesn’t just work with us on this: it’s helped on the race car,” says Kato.