Designed for powering large touring and intercity coaches, the new X12 engine with up to 480 HP (360 kW) output incorporates innovative architecture and a highly efficient in-cylinder combustion formula, eliminating the need for exhaust gas recirculation (EGR). It is a next-generation evolution of Cummins 12 litre Euro V engine, proven worldwide as the ISG12. This includes techniques to minimise friction losses throughout the engine and a weight-saving sculptured engine block, resulting in a remarkably low weight less than 920 kg, but with the heavy-duty strength and uncompromising on-road performance required for 12-15 metre high deck coaches.
The high flow air-handling system gives a faster pedal response to enhance driveability, and high peak torque of up to 2,300 Nm is delivered across a wide engine speed range. Equally powerful is engine braking with 370 HP (275 kW) delivered at 2,100 rpm. “The X12 will set a new benchmark in its class by providing unprecedented levels of performance for coaches in Europe and markets around the world as they transition to meet Euro VI equivalent emission standards,” said Brian Wilson, Executive Director – Global Bus Business, Cummins. At the expo, the King Long C13HD High Deck coach on display was powered by this engine which has now entered production, he noted.
The EGR-free combustion lowers heat rejection by around 40% compared with that of similar engines using cooled EGR, allowing the full power potential of the X12 to be realised while meeting Euro VI Phase D emission standards. The engine takes advantage of Cummins’ latest U-module compact box after-treatment with integrated AdBlue dosing, providing more simplified vehicle integration. Active regeneration of the after-treatment is reduced to a minimal level and service cleaning intervals are extended.