Fully Automatic Transmissions for Airport Vehicles

Direct control of engine torque through Shift Energy Management enables increased torque rating for buses with no increase in weight or size

Shanghai, China – Allison Transmission has announced the addition of new T390 and T390R models to the proven Torqmatic® Series of fully automatic transmissions for bus applications.  These latest models use a high level of powertrain integration to enhance torque capacity, durability, shift quality and economy.  To support a continuing trend for ever increasing engine power and torque, Allison is implementing Shift Energy Management (SEM) to dynamically manage torque through the transmission.  By seamlessly modulating the engine torque before the shift is engaged, clutch energy and thus temperatures are lowered, increasing durability and offering higher ratings capability.  In the case of the new T390 and T390R city bus transmissions, SEM provides a 200Nm increase in input torque ratings compared to the T375 and T375R models.

“Power and torque levels continue to rise, yet bus OEMs want to retain the size and weight advantages our transmissions offer,” says Rich Price, Director of Asia Pacific Engineering. “SEM means Allison can provide OEMs with a transmission that satisfies design and operational requirements needed today in some global markets, while preparing for future growth in others.”  Allison’s new T390 and T390R models are ideally suited to city buses and coaches with engine ratings up to 380 HP and 1650Nm.  Additionally, the new T390R transmission includes an output retarder feature for enhanced vehicle braking.

Introduction of SEM ensures the most effective utilization of Allison’s fuel economy software features. “SEM makes the most of Load Based Shift Scheduling (LBSS) and enables new features such as Super Economy Shift Scheduling (SESS) and Vehicle Acceleration Control (VAC),” adds Price. SESS, developed by Allison, monitors operating conditions and automatically upshifts to a higher gear as soon as tractive effort requirements are met.  This feature allows the bus to remain in the highest gear as long as possible, even during slower speed operation to maximize fuel economy.  VAC is focused on driver input and controls acceleration to maintain a smooth, fuel efficient acceleration rate for specific controlled duty cycles or fuel efficiency benefits.  “Together with proven technologies such as Auto Neutral and Reduced Engine Load at Stop (RELS) available across our Torqmatic® Series of bus transmissions, Allison offers a comprehensive range of tools for optimizing bus fleet fuel efficiency,” concludes Price.

About Allison Transmission, Inc.

Allison Transmission, Inc. (Allison) is the premier global provider of commercial duty automatic transmissions and hybrid propulsion systems. Allison products are specified by over 250 of the world’s leading vehicle manufacturers and are used in many market sectors including bus, refuse, fire, construction, distribution, military and specialty applications. Founded in 1915, the Allison business is headquartered in Indianapolis, Indiana, U.S.A. and employs approximately 2,900 people. Regional headquarters with dedicated support staff are located in China, The Netherlands, Brazil, India and Japan. With a global presence in 80 countries, Allison has over 1,500 distributor and dealer locations. More information about Allison is available at www.allisontransmission.com.