The Speed 400 features an all-new 398.15cc liquid-cooled single-cylinder engine. It produces 40PS at 8000rpm and 37.5Nm at 6500rpm. The engine is mated to a 6-speed transmission with a slip-and-assist clutch. Triumph offers a generous 16,000km service interval for the Speed 400, and the claimed mileage stands at 28.3kmpl