Allison Plans Nine-Speed Transmission With Start-Stop Technology
ATLANTA – Allison Transmission announced plans to introduce a nine-speed automatic transmission for medium and heavy-duty vehicles that features start/stop technology, and which will be available globally by 2020.
The transmission is being developed for Classes 3–7 vehicles and is ideally suited for distribution trucks, rental and lease applications and school buses, said Randy Kirk, Allison’s senior vice president for product engineering and product teams, during a press conference here at the North American Commercial Vehicle show.
Kirk noted that specific features in the unit are designed to improve fuel efficiency. Those features include a deeper first gear, expanded gear ratios, smaller steps between gears and early first gear lockup of the torque converter, he said. “The torque converter improves overall transmission efficiency when it locks up sooner,” he said. “This enables the engine to run at lower speeds sooner, and this reduces fuel consumption.”
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The nine-speed will also feature an integral, multi-function engine stop-start system, Kirk said. “Beyond fuel consumption benefits of shutting off the engine when the vehicle is stopped, the system also provides immediate transmission engagement and vehicle hold while the engine is restarted,” Kirk said.
It also has next-generation “intelligent” shift controls that can learn how to optimize a vehicle’s performance based on usage, he said. “This newly-developed control system incorporates learning algorithms and other proprietary capabilities to establish and then benchmark, by finding the ideal balance of fuel economy and performance for a vehicle,” he said.
The combination of the transmission’s base design features and the advanced controls will deliver up to 7% fuel economy savings versus the Allison six-speed, and up to 10% or more versus competing units, he said.
“This innovative model leverages industry-leading ratio coverage, advanced engine stop/start and our latest generation electronic controls all to improve fuel economy and reduce emissions,” Kirk said.
During the development process for the transmission, Kirk said Allison heard from fleets in North America, Europe and Asia who are interested in the unit, but he would not commit to specifics on where the unit might first be launched.
He did say, however, that the transmission is “an important enabler” to help OEMs comply with global emissions regulations. “This nine-speed product launch represents the first in a number of new products which will demonstrate Allison’s ongoing commitment to addressing the global challenge of improved fuel efficiency and reduced greenhouse gases,” Kirk said.
