The first new Voith Turbo Euro 6 automatic gearboxes are being fitted to Stagecoach buses and will be operating in the UK by the end of the year.
The DIWA.6 will be married to the Euro 6 Cummins six-cylinder ISB engine in 29 ADL Enviro 400 MMC double-deck Stagecoach buses which will go into service in Manchester.
The order for the DIWA 854.6 gearboxes is part of an order for new vehicles that was announced by Stagecoach earlier this year.
Stagecoach UK Bus Regional Director, Sam Greer, said: “This new vehicle order for Manchester is our largest Euro 6 order to date and we are pleased to be using the new Euro 6 Voith transmission because we believe it is one of the most efficient and highest performing on the market.”
Voith said the new DIWA.6 will reduce noise emissions, provide better thermal stability, and will improve efficiency. It has been designed for double-deckers, single-deckers, and the midi-bus sector.
John Domigan, Voith Turbo’s Sales and Marketing Manager, said: “The new DIWA.6 will contribute to improved fuel efficiency of up to 5%. It also has a number of additional benefits. For example, the operating pressure automatically adjusts to the output required during the stop-start cycle of a bus so that pressure can be reduced whenever possible.
“In addition, when the vehicle is stationary the automatic shift into neutral separates both the transmission mechanics and the converter from the engine. This allows minimum fuel consumption.”
The design changes to previous models include modifications to the gear pump, heat exchanger, converter pump, working pressure valve, acoustics and housing, and stop-start preparation. The new planetary carrier is lighter but maintains the same strength as previous models.
Voith Turbo makes automatic transmissions specifically for the stop-start cycle of buses. The DIWA’s first gear replaces the first two gears on a conventional automatic gearbox cutting fuel consumption. It reduces gear shifts at lower speeds giving a more comfortable ride for passengers.
