Twenty years ago, a Staffordshire construction equipment manufacturer did something nobody expected. JCB built a land speed car, took it to the Bonneville Salt Flats in Utah, and set a diesel land speed record of 350.092mph that has never been beaten. The driver was RAF Wing Commander Andy Green, the only person in history to break the sound barrier on land, having piloted the jet powered Thrust SSC to 763.035mph in 1997. Now JCB is going back, Green is going back, and this time the fuel is hydrogen.
The car is called the Hydromax. It is 32 feet long and was built over five years at a cost of £100 million, developed with Prodrive, the Oxfordshire engineering firm behind some of the most capable rally and motorsport machinery on earth. Two hydrogen combustion engines sit at its core, each producing around 800hp in record trim, combining for a total output of 1,579bhp. Those engines are mechanically close to units that now power production JCB diggers, with chief engineer Lee Harper telling Autocar the internals are "very similar." The same engines produce around 80bhp each in standard form. Getting from 80 to 800 is a matter of getting fuel and air to mix properly at extreme pressure, according to Harper, and the Hydromax achieves that with bespoke intercoolers, radiators and racing specification turbochargers.
Power goes to all four wheels through a twin transmission and clutch system. The body has been refined for aerodynamic stability at speeds the previous car was not designed to exceed. Every suspension component, traction control setting and camera placement has been stress and simulation tested before a wheel turns on salt.
The record the Hydromax is primarily chasing is its own predecessor's. Lord Bamford, JCB's chairman, has stated the aim plainly: beat 350mph. Beyond that sits the existing hydrogen land speed record of 302.877mph, set by the Buckeye Bullet 2 fuel cell vehicle in 2009, and the hydrogen combustion record of 185.5mph set by BMW's H2R prototype in 2004. The Hydromax is not competing in the fuel cell category. It burns hydrogen in a combustion chamber, which is a different and more directly relevant technology for the construction industry JCB serves.
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UK testing begins next month. The team then heads to Bonneville Speedweek, running from 1 to 7 August, where competitors from around the world gather to chase records on the salt. Official FIA record runs will follow immediately after. The available track at Bonneville is now nine miles long, two miles shorter than in 2006. JCB says the Hydromax's superior power to weight ratio over the Dieselmax will compensate.
Green, who will be 64 when the car makes its attempt, said:
"Hydromax is lighter, more powerful and faster than its predecessor of 20 years ago. Once again, we're going to show the world just how good British engineering and technology really is."
Lord Bamford put the broader point this way:
"If you're serious about emissions, you have to be serious about hydrogen. And a land speed project is the perfect way to prove it."
JCB has been running hydrogen diggers on commercial construction sites since 2025, making it the first company to deploy hydrogen combustion machinery outside a test environment anywhere in the world. The Hydromax is not separate from that programme. It is the sharp end of it.
A digger maker going 350mph on a salt flat to prove a point about heavy equipment emissions is, objectively, one of the better things happening in the automotive world right now.
Sources:
- Autocar — JCB targets new speed record with 32 foot-long, 1579bhp Hydromax
- JCB official — Introducing the JCB Hydromax
- Auto Express — Insane JCB Hydromax targets 350mph
- Top Gear — JCB is back with the Hydromax: can it hit 400mph?