Voith cuts fuel usage by 10% with stop-start tech

Benefits from DIWA.6 gearbox in ADL E200 MMCs means that 96 E400s will have the same functionality

The DIWA.6 gearbox has improved efficiency by 10% in NXWM E200s

The first buses in the world fitted with Voith Turbo’s pioneering stop-start technology have improved fuel efficiency by up to 10% in their first year in service in Birmingham with National Express West Midlands (NXWM)

Two single deck Alexander Dennis Enviro200 MMC buses, equipped with the new technology on the Voith DIWA.6 transmissions, have already clocked up over 80,000 fault-free miles on the 37 route between Solihull and Birmingham city centre.

Following this success NXWM has ordered 96 Enviro400 MMC double-deckers fitted with Voith DIWA.6 gearboxes with stop-start technology. They are being delivered at the rate of five a week until completion in December.

“Our company is totally committed to playing a full part in helping to clean up the air in the centre of Birmingham, so fitting stop-start technology to our buses is imperative,” says Colin Saward, Head of Operational Engineering for NXWM

“Voith is the only transmissions specialist with this proven technology in service. During trials we didn’t see a single Voith engineer which means our buses are more reliable and our passengers are increasingly satisfied with the service we offer.”

During normal operating conditions – including bus stops, red traffic lights and heavy traffic – city buses spend up to 40 per cent of their time in idling mode. The DIWA.6 stop-start technology automatically disengages its driveline which reduces fuel consumption and emissions.

With the stop-start technology DIWA.6 transmissions can stop for up to 60 seconds without influencing the start-up readiness of the bus – saving between five and 10 per cent on fuel depending on the duty cycle.

John Domigan, Voith Turbo Sales and Marketing Manager, says: “We are delighted with the work we have carried out with National Express to reduce operating costs and produce a cleaner environment in Birmingham.