Allison Transmission > Commercial Products > Hybrid Bus
Hybrid Bus
Since being introduced in 2003, Allison Hybrid H 40 EP™ and H 50 EP™ equipped buses have traveled over 100 million miles without a single "end-of-life" battery failure. They have saved an estimated 15 million gallons of fuel. And, eliminated over 151,000 metric tons of CO2.
Hybrid Bus Ratings
Allison H 40 EP Drive Unit - Transit Bus
Continuous:
280 hp (209 kW)
Rated Input Torque:
910 lb-ft (1234 N•m)
Rated Input Speed:
2300 RPM
Allison H 50 EP Drive Unit - Suburban Coach / Articulated Bus
Continuous:
330 hp (246 kW)
Rated Input Torque:
1050 lb-ft (1424 N•m)
Rated Input Speed:
2300 RPM
Customer Profile
The Pinellas Suncoast Transit Authority (PSTA) provides public transportation services to around 40,000 riders a day in Pinellas County, Florida, which includes the St. Petersburg, Clearwater and nearby beaches on the Gulf of Mexico. According to Brad Miller, CEO of PSTA, "Our fuel budget of more than $6 million a year, outside of our labor costs, is our number one greatest expense." So, having Allison Hybrid buses that deliver greatly improved fuel economy, compared to their conventional diesel buses, is a huge benefit.
System Components
H 40 EP / H 50 EP Drive Unit
Same proven form, fit and function.
- Two-mode parallel hybrid operates automatically as a parallel hybrid or series hybrid
- Continuously variable drive with an infinite number of ratios
- Automatically adjusts ratios to operate at optimum power curves to attain best performance and fuel economy
ESS2 (Energy Storage System)
The latest Nickel Metal Hydride battery cell technology from PEVE is utilized in this second-generation unit.
- Common, high-capacity hardware to handle every bus size
- First generation ESS achieved over 100 million miles of revenue service without any end-of-life battery cell failures
- New technology proven durable and reliable to avoid risks associated with experimental energy storage devices
Fourth Generation Electronic Controls
The latest commercial high-volume, high-quality controller features common hardware to all the latest Allison transmissions and hybrids.
- Greater processing power and memory capability
- Memory expansion allows for further technology evolution
- Fewer electrical connections for greater system durability and reliability
- Full optimization with latest engines
- Allison HyValue™ performance features HyGain™, HyIdle™ and HyTraction™
DPIM2 (Dual Power Inverter Module)
The second-generation unit features more robust internal hardware with enhanced redundancy for greater reliability. Externally, this unit is fully interchangeable with all prior production units.
Fast, Smooth Acceleration
A bus equipped with the Allison Hybrid EP system significantly out-accelerates a similar bus equipped with a conventional drivetrain or an alternative fuel system. The acceleration is smooth and seamless. Drivers and passengers prefer Allison Hybrid to standard buses because the ride is smooth and comfortable.
With Allison's HyGain™ feature, a transit property can adjust the acceleration rate to fit their operating requirements. Adjusting HyGain downward further increases fuel economy.
Easy Installation, Easy Maintenance
2011 Allison Hybrid EP system components fit in virtually the same space claim as a conventional drivetrain. This compact package easily installs in T-drive driveline layout. The drive unit was designed to resemble an Allison Bus Series transmission so maintenance training and repairs are easier. The H40 EP and H 50 EP share common parts to minimize fleet inventory.
