UPS is introducing composite materials to replace certain metal components into its trucks, a move that is improving the company's fuel efficiency by 40%, according to a UPS blog post.

The company is purchasing 150 of these vehicles after testing five CV-23 composite prototypes in a year-long pilot program to determine durability, repair qualities and structural strength. The vehicles, nicknamed the "plastic trucks," weigh nearly 900 pounds less than traditional package cars, improving fuel efficiency by 40%, according to test results. Vehicle delivery is scheduled for the fourth quarter of 2012.

One year of testing five of these vehicles in high-mileage settings showed that composites stand up to the rigors of the road. According to the company, they are durable, work well in various climates (especially where corrosion from road salt is a problem) and are easily repairable because they are modular.

With such significant fuel savings, composites rival the fuel efficiency of alternative fuel vehicles - minus the infrastructure issues, production challenges and technology obsolescence concerns that go along with alternative fuel vehicles. UPS plans to test composites in larger, heavier vehicles to see if they provide the same benefits.

The use of composite materials signals a strategic shift for UPS. In the past, the company's blog says, UPS package cars were "built like tanks" because they were kept in service for decades. Now, though, the company is changing its mindset.

UPS isn't the only company advocating the commercialization of light-weight composites. Manufacturers of passenger cars are also composites, and the U.S. Department of Energy will provide $14.2 million in funding for fuel-saving projects, including those using new materials to decrease vehicle weight.

Composites aren't the only way UPS is increasing fuel efficiency. "Our 'rolling laboratory' strategy leverages our on-the-road development programs to check out all avenues for reducing fuel consumption and emissions," says Dale Spencer, director, automotive engineering. "Since the year 2000, UPS has improved its U.S. fuel efficiency in miles per gallon by more than 20%."

The company is also collaborating with dozens of vehicle manufacturers to develop more structural and operational ways to cut vehicle weight, improve mpg and increase fuel efficiency, including prototype hoods that improve aerodynamics; perforated mud flaps on tractor-trailers to fight wind resistance; and telematics to help reduces the miles the vehicles travel to deliver packages.

Alternative fuel and advanced technology vehicles are also part of the company's strategy, with more than 2,500 now on the road.