REFINING TORQUE

Yanmar's 3JH5E was always the odd man out compared to its tractor-based competition where most engines in its power range had four cylinders and indirect injection. Indirect injection was primarily used to reduce exhaust emissions in land-based machinery, and, because fuel is injected into a pre-combustion chamber, to reduce vibration levels. But as the 3JH5E was a dedicated marine engine, Yanmar could use direct injection instead, which uses less fuel for output.

The trouble was, the maximum torque peaked early in the rpm range, which was fine for manoeuvring a hefty cruising yacht around a marina, but not so efficient for cruising. So Yanmar re-designed the 3JH5E to take electronically managed common rail injection and morphed the engine into the 3JH40 CR.

Instead of maximum torque being produced at 1800rpm, it's now at 2000rpm