Engineering a monster: how JCB built the world’s fastest tractor

British heavy-machine giant JCB has just rewritten the rulebook on what a tractor can do. In 2019 the company’s Fastrac Two—an aerodynamically brutalised, 5-tonne evolution of its 8000-series Fastrac—set a new two-way average land-speed record of 135.191 mph on a disused runway in the UK. Guinness World Records confirmed the feat after the tractor hit a peak of 153.771 mph in both directions, eclipsing its own domestic record of 103 mph set earlier that year by the slightly less extreme Fastrac One. Behind the wheel was TV presenter and stunt driver Guy Martin, while the tractor itself was the result of a full-throttle engineering blitz that turned a 43-mph workhorse into a diesel dragster.

The heart of the beast is a turbocharged 7.2-litre six-cylinder diesel that JCB already builds for its 672-series engines. In Fastrac Two guise it’s tuned to 1,016 HP and more than 1,844 lb-ft of torque, revving to a 3,400-rpm redline. Power is sent through a ZF lorry-spec six-speed manual transmission with long throws to a spool differential on the rear axle. Exhaust gases exit via a 3D-printed Inconel system that can survive 1,832 °F, while the entire machine rides on a bespoke aero bumper, front splitter and rear diffuser developed with Williams Advanced Engineering. The cab itself is 200 mm lower and 300 mm narrower than stock, and the whole tractor sits 200 mm closer to the tarmac, cutting its drag coefficient to 0.48—remarkable for a 5-tonne tractor that normally tips the scales at 8.5–9 tonnes depending on spec.

To hit the target weight JCB stripped out non-essentials: no big starter battery, no air-brake compressors. Stopping power comes from disc brakes at all four corners backed by a small parachute. Tyres were another critical focus; BKT built bespoke carcasses with shorter tread blocks and narrower profiles, then validated them on an aircraft test rig at 160 mph. The result is a machine that not only claims the world’s fastest modified tractor title but also underlines JCB’s broader land-speed pedigree—it already holds the outright diesel-vehicle record at 350 mph.