TheAllison Bus Series of transmissions are designed for medium duty and heavy duty buses. Each type is available in 5 or 6 speeds with a retarder as an option. There are six models in the Bus Series. The main differences between them are listed below.

In 2015, Allison introduced a new model in the Bus Series. Part of the xFE (extra fuel economy) line, the B3400 xFE incorporates optimized gear ratios and features the FuelSense® Max electronic control package. New gear ratios also allow the torque converter to lock up at lower speeds. The xFE transmissions boast an up to seven percent improvement in fuel economy over baseline models.^[1]

Comparison between xFE vs non-xFE

• The xFE is a new transmission complete with new gear ratios and new electronics. The aim at the xFE is to improve fuel effiency even further

• The xFE offers several software opitions which optimizes fuel savings -
  • Dynamic Shift Sensing - Much simliar to LBSS, this controls shifting based upon terrain
  • EcoCal - software to enable torque converter to lockup sooner versus non-xFE
  • Neutral at Stop
  • Acceleration Rate Management - dicates how much torque the engine puts though the flywheel depending on terrain and load

Models

References

• Allison