With gas prices on the rise again, UPS is testing a new lightweight delivery truck that could be 40 percent more efficient than its current vehicles.

Made from a plastic-like composite material, the new trucks are approximately 1,000 pounds lighter than the shipping company’s traditional trucks and have a smaller, more efficient diesel engine.

The new composite trucks offer other benefits in addition to improved fuel economy, UPS says. Manufacturing the new truck uses less energy than producing typical vehicles, and no paints are used, making the new truck’s construction eco-friendly. The truck’s bumpers, fenders and side cladding can be easily replaced if they are damaged, rather than requiring body repair work.

UPS began using the new trucks last month in five locations across the country and will conclude its testing in December. Cities in Nebraska, Arizona and New York were chosen as test sites to evaluate the truck’s performance under a variety of weather and road conditions.

UPS already has a fleet of 2,000 alternative fuel vehicles, including natural gas, propane, hydrogen fuel cell and hybrid electric vehicles. The new composite trucks give the company another eco-friendly option: They will cut down on fuel use, but are not dependant on the still-growing alternative fuel infrastructure.