Allison Transmission > Commercial Products > Fuel Efficiency
Fuel Efficiency
Fuel Consumption Testing
With the continuing volatility of fuel prices, there's naturally a concern about what truck components can contribute to reducing fuel consumption. The transmission, as a major driveline component, is an important factor in driveline efficiency. Fully automatic Allison transmissions, along with a vehicle spec appropriate for the particular duty cycle, can provide superior fuel efficiency and optimum fuel economy. But, all things being equal, how do Allison Automatics stack up against automated manual transmissions? To find out, Allison commissioned an independent, third-part test facility to conduct Fuel Consumption Testing.
Full Power Shifts
Allisons accelerate faster and get more work done in less time than manual and automated manual transmissions. Manual and automated manual transmissions disconnect from the engine when making shifts. It’s just inherent to their design. They actually reduce engine torque and slow down when making a shift. That means during a typical acceleration – like each time you pull away from a stop sign – manual and automated manuals decelerate over 35% of the time. Only one type of transmission offers true full power shifts – a torque converter-equipped automatic. An Allison Automatic transmission is a true automatic.
Load-Based Shift Scheduling (LBSS)
With years of research and testing, Allison engineers have developed over 100 shift schedules, or ways to electronically control the shifting of the transmission. These schedules ensure that the transmission is optimized for both the engine characteristics and the duty cycle of a particular vehicle. Allison continues to strive for the optimum balance between Performance and Economy. In fact, many vechicles are equipped with dual-shift schedules so that you can manually switch between Performance and Economy mode. Allison's Load-Based Shift Schedule feature automates this process. Check with your Allison representative to find the ideal shift schedules for your operation to maximize your fuel efficiency.
LBSS is available on the following models:
2010 Hardware Updates
Several 2010 hardware enhancements to all 1000 and 2000 models have produced a more robust and optimized transmission. This not only leads to longer transmission and vehicle life – it also results in more efficient operation that helps improve fuel economy.
Reduced Engine Load at Stop (RELS)
With Allison’s RELS feature, the transmission automatically reduces the load on the engine when the vehicle is at a full stop. RELS not only saves fuel – it reduces overall vehicle emissions. This feature is useful for city traffic and duty cycles with frequent stops forcing the engine to idle.
RELS is available on the following models:
Park Brake Automatic Neutral
Park Brake Automatic Neutral automatically shifts the transmission to Neutral when the park brake is applied. Since there’s no need to keep the transmission in Drive if a vehicle is sitting idle, this feature shifts to Neutral to save fuel. It requires the operator to reselect Drive – an added safety feature. Consult your OEM representative for availability.
Increased Lockup Availability
Allison B 300 and B 400 models equipped with this feature are able to shift into lockup in 1st range, and lockup stays on through 1st to 2nd shift. The transmission's electronic controls monitor acceleration to determine when to activate lockup.*
*Application engineering review is required for this feature.
Vehicle Acceleration Control (VAC)
VAC controls aggressive driving practices to improve overall fuel economy for Pupil Transport/Shuttle Series and Bus Series transmissions. VAC limits acceleration by controlling amount of engine torque based on vehicle load. Tests using a simulated bus duty cycle showed VAC helps improve fuel economy by up to 3%.*
*Results may vary depending on operating conditions.
VAC is available on the following models:
