Besides the aerodynamics and generation of sufficient horsepower, the other crucial area for any wheel-driven land speed record contender is the tyres. The thorny problem of sourcing them fell to David Brown, project chief engineer.

“After the salt conditions, the tyres are the biggest challenge,” Brown says. “It is critical to have the right rubber, because you cannot play Russian Roulette with a man’s life.”

He immediately discovered two things. Those tyres that were available commercially had varying technical data to facilitate informed opinion as to their suitability for supporting a 2700 kg car travelling at 300+ mph. Tyre data should include maximum speed, load rating and running pressure; most proprietary Bonneville tyres come only with a speed rating and no further indication of how that was calculated.

The appropriate tyres were finally found and rig tested to ensure JCB DIESELMAX can run at 300mph-plus.