Big Brown goes green

The trademark brown UPS delivery trucks making the rounds in Michigan over the past few months may look like any other UPS vehicle. But there's something a little different under the hood—or in the powertrain, to be precise. UPS has been testing a first-of-its-kind hydraulic hybrid diesel urban delivery truck, which is billed as the world's most fuel-efficient and cost-effective delivery vehicle. The hydraulic hybrid truck was developed through a partnership between the Environmental Protection Agency (EPA), the U.S. Army, UPS, International Truck and Engine Corp. and Eaton Corp.

The vehicle, which was unveiled in late June, is expected to improve fuel efficiency by 70 percent in urban driving and cut greenhouse gas emissions by 40 percent, according to the EPA. It features a full hydraulic hybrid powertrain and a unique hydraulic hybrid propulsion system integrated with the drive axle.As with other hybrid systems, energy saved when applying the brakes is reused to help the vehicle accelerate.

The EPA estimates that the technology could save more than 1,000 gallons of fuel per vehicle each year. The net savings over the vehicle's lifespan could exceed $50,000, assuming current fuel prices.