What are the Environmental Savings?
The buses reduce fuel consumption by an average of 30 percent, lower maintenance costs by 30-50 percent, run with less engine noise and minimize diesel exhaust odor.

In addition to helping reduce greenhouse gas emissions, believed to contribute to global warming, the hybrid electric buses will reduce particulate matter, carbon monoxide and hydrocarbon by up to 90 percent and carbon dioxide and nitrogen oxide by up to 50 percent.

What are the Cost Savings?
Converting 20 of its buses to hybrid electrics will save the AATA 811,200 gallons of fuel and save close to $2.5 million over the buses 12-year life expectancy.

Additionally, the hybrid electric buses will reduce fuel consumption by an average of 30 percent compared to conventional diesel buses. Maintenance costs will also be reduced by 30-50 percent, due to reduced stress. Maintenance on mechanical components will be reduced, including the doubling of the life of the brakes, the elimination of transmission maintenance and decreased wear on suspension.

How Much Fuel will be Saved?
Converting 20 of its buses to hybrid electrics will save the AATA 811,200 gallons of fuel and save close to $2.5 million over the buses 12-year life expectancy.

Will Passengers Notice a Difference?
Passengers will notice an improvement while riding the new hybrid electric buses. The buses run with less engine noise, due to a quiet electric motor and smaller diesel engine. Passengers will also notice a decrease in diesel exhaust odor and improved road performance as the buses deliver 50 percent better acceleration than conventional diesel buses.

How Does the Hybrid Electric Engine Work?
The new bus engine has a hybrid electric drive supplied by Allison Transmission, a division of General Motors. The hybrid electric system determines the most efficient way to propel the bus into motion. The hybrid electric system is a combination of a battery-powered electric motor to provide most of the power at slower speeds and a smaller clean-diesel engine that takes over at higher speeds.

The Allison parallel system provides both a mechanical and an electrical path through the drive unit. As the bus accelerates from a stop, electric drive predominates. The mechanical drive gradually blends with the electric drive until, at highway speeds, the drive is purely mechanical.

How Do These Buses Fit with the Rest of AATA's Fleet?
The introduction of hybrid electric technology is by far the AATA's most aggressive move toward ensuring a cleaner environment; the AATA converted its fleet to ultra low sulfur diesel fuel in 2002 and to a blend of five percent biodiesel with ultra low sulfur diesel fuel earlier in 2006. AATA is currently testing a blend of ten percent biodiesel with ultra low sulfur fuel.