With 93 buses, Verkehrsbetriebe Zürichsee und Oberland AG (VZO) carries an impressive 21.5 million passengers per year. And the trend is upward. The buses travel approximately 6.6 million kilometers annually. Improving efficiency and conserving resources are key concerns for VZO. The company approached MOTOREX in hopes of harmonizing the oil change interval of its 52 articulated buses with that of its 35 standard buses. The solution: ATF VZ.

VZO is a member of the Zurich regional transit alliance ZVV, responsible for public transportation across the 250 square kilometers of the Zürcher Oberland, the right shore of Lake Zurich and Rapperswil-Jona.

The maintenance crews at VZO wanted to be able to operate the two different types of transmission in their buses for 120,000 kilometers using one and the same automatic transmission fluid. This would mean extending the 60,000 kilometer fluid change interval of the articulated buses to equal the 120,000 kilometer interval of the standard buses. The goal of doubling service life in the articulated buses while halving fluid change intervals promised numerous benefits:

  • Improving vehicle dispatching
  • Cutting down time
  • Lowering maintenance costs
  • Simplifying logistics
  • Conserving resources, etc.

Both the standard and the articulated buses are Mercedes-Benz Citaro models. The standard buses are equipped with Voith Diwa 5/6 transmissions, while the articulated buses use ZF Ecolife transmissions. The bus routes involve lots of stop-and-go operation, speeds of up to 80 kph and in some cases challenging ascents and descents.

MOTOREX ATF VZ synthetic automatic transmission fluid was developed in collaboration with VZO’s Technical Service, an additive producer and other transmission engineering specialists. The fluid was tested in extensive field trials at VZO and approved after meeting the leading transmission manufacturers’ requirements (see box: Specifications).

«MOTOREX ATF VZ measurably contributes to improving the efficiency of our vehicle fleet.»
Urs Ryffel, VZO Shop Manager , Grüningen

Especially in bus transmissions, automatic transmission fluid is an important factor in several different ways. For one thing, the fluid is responsible for hydrodynamic transmission of forces and for the essential engine braking effect. For another, these transmissions are designed for high torque and allow shifting with nearly imperceptible steps between gears. The lubricant is subject to very high shear forces across temperature ranges from below zero to as high as +105 °C in the oil sump. MOTOREX ATF VZ was specifically formulated for the requirements of Voith (Diwa 5/6 ) and ZF (Ecomat and Ecolife) bus transmissions. It displays extremely high shear stability, high resistance to aging and an exemplary load-bearing capacity. Its base oil and additives provide outstanding performance reserves, guaranteeing full performance over at least 120,000 kilometers.

Innovative lubricants like MOTOREX ATF VZ are a sign of the times, boosting efficiency in public transit.