UPS says its fleet of alternative-fuel vehicles - already the industry's largest - has expanded with the deployment of 50 next-generation hybrid electric delivery trucks.

The 50 hybrid electric vehicles (HEVs) will operate in Atlanta, Dallas, Houston and Phoenix. These new trucks join roughly 20,000 low-emission and alternative-fuel vehicles already in use.
The HEV fleet will feature two different size vehicles from Workhorse Custom Chassis and Freightliner LLC and a hybrid power system from Eaton Corp.
"We're excited to be among the first to deploy the latest in HEV technology because it promises a 45 percent increase in fuel economy in addition to a dramatic decrease in vehicle emissions," said Robert Hall, director of UPS ground fleet engineering.
The 50 new HEV package cars are expected to reduce fuel consumption by roughly 44,000 gallons over the course of a year compared to an equivalent number of traditional diesel trucks. The hybrids also should reduce by 457 metric tons the amount of CO2 gases released annually into the atmosphere.
The new hybrid power system allows UPS to use a smaller diesel engine than would be required in a conventional delivery truck, thus saving on fuel and pollution-causing emissions. A battery pack, motor/generator and power control system are added, which allows electric power to be fed into the powertrain when conditions demand it, providing further savings.
The hybrid electric vehicles also use what is known as regenerative braking, meaning the energy generated when stopping the moving vehicle is captured and returned to the battery system as electrical energy. The efficient, computer-controlled combination of clean diesel power, electric power and regenerative braking allows dramatic improvements in fuel savings and emissions reductions. The external truck bodies will be identical to the company's other signature brown trucks, although they will feature additional script on the side identifying them as hybrid electrics. The trucks will operate with lithium ion batteries, which offer a faster re-charging capability and last longer than batteries used in previous generations of HEVs. Additionally, these vehicles are much quieter than conventional UPS trucks.
UPS has agreed to work with the U.S. Energy Department over the course of 2007 to share the vehicles' fuel economy, emissions and other performance data.
The UPS alternative fuel fleet currently includes trucks powered by compressed natural gas, liquefied natural gas, propane and electricity. UPS also has been testing hydrogen fuel cell vehicles and hydraulic hybrid technology in partnership with the Environmental Protection Agency and others. Just since 2000, the alternative-fuel fleet has traveled more than 126 million miles.