CUMMINS ANNOUNCES STOP-START SYSTEM FOR BUSES AND COACHES
It promises to reduce fuel consumption by between 4% and 7% depending on duty cycle and cut NOx emissions by between 30% and 40%. This was unveiled at Busworld Kortrijk exhibition, where Cummins unveiled the system for Europe. For the American market it was already launched last year.
One of the first vehicles fitted with the new system is this ADL Enviro400 MMC in the Stagecoach fleet which has been on test in Liverpool. The launch comes as Cummins tries to reduce total cost of ownership for operators and learns ever more about the varied demands of different duty cycles. Developing the system has involved changes to the engine hardware and a great deal of software development. Among the changes are among others a new flywheel and ring gear, and an improved starter motor.
Proving the system in service has been approached very thoroughly and over 4,250,000 stop-starts will have been performed by the time of the launch. Field tests are currently under way involving eight vehicles and six manufacturers. Among these is an ADL Enviro400 MMC, with 250hp engine and four-speed Voith DIWA transmission. As well as bus applications, Cummins believes there is scope for stop-start in truck applications and has the equipment fitted to a truck running in its own fleet.
Obviously, all of this additional starting and stopping increases the demand on the starter motor and to this end the normal unit designed for 30,000 starts has been replaced with one with a 210,000 start design capacity.