ZF – improved driving dynamics
THE ZF-ECOLIFE six-speed automatic transmission lives up to its reputation as universal genius once more, its states. Thanks to the new start-stop function, city buses consume up to 10 per cent less fuel. An additional transmission variant called EcoLife Coach is particularly suitable for higher input torques of up to 2300Nm and therefore for intercity and coach applications.
For sophisticated coach tours there’s the ZF-EcoLife coach for torques up to 2300Nm. ZF-EcoLife is the worldwide benchmark for automatic bus transmissions used in the most demanding application area – the city traffic, it’s stated. Based on this, the technology company is expanding the transmission family with the ZF-EcoLife Coach version. This is specifically designed for use in intercity buses and coaches and for particularly demanding routes. The torque converter in the ZF-EcoLife Coach transmits input torques of up to 2300Nm – and thus the comparably high performance of coach engines.
In mountain regions, for instance, intercity buses and coaches must frequently brake hard due to frequent narrow bends and must then accelerate strongly again. For this reason, many gear changes in a short period of time are required – just like in city traffic. This is where ZF’s EcoLife Coach benefits from its high efficiency and its smooth and efficient acceleration without tractive force interruption when changing gears. Speed and accelerative force do not drop off either, which has a positive effect both on fuel consumption and noise emissions.
When driving downhill, ZF’s primary retarder pays off: this system is the only one that develops its braking effect depending on the engine speed and not, as conventional secondary retarders do, in relation to the vehicle velocity. Thus, the retarder also efficiently decelerates on long downhill routes and at low bus velocities, increasing safety and reducing the wear of the service brakes. As a result, combined with the innovative cooling concept, it is possible to apply the retarder for a very long time without reduction, and to use it almost until vehicle standstill.
A current trend gives further reasons why to opt for ZF-EcoLife Coach: many coaches also drive often in cities for long, continuous stretches of time. For instance, when they are used as shuttles between city hotels and the airport or for sightseeing at the destination. In both cases, the buses and their transmissions have to tackle both low speeds and frequent gear changes in stop-and-go traffic. In this way, the ZF-EcoLife Coach optimally combines the requirements of coaches with the driving situation of city buses. EcoLife Coach went into volume production in fall 2016 and has been continuing ever since (at MAN and Irizar, among others). EcoLife Coach will also go into volume production with its new generation of engines at VDL and Van Hool very soon.