Red Bull, the maker of energy drinks, is investing in new energy-saving hybrid trucks.

Four International DuraStar Hybrid trucks were delivered to Red Bull's Southern Nevada Distribution Center in Las Vegas and will be used in the Las Vegas metropolitan area.

The diesel hybrid electric trucks achieve 30-40 percent better fuel efficiency and emit up to 33 percent less hydrocarbon emissions and 35 percent less nitrogen oxide emissions versus standard diesel trucks, according to the manufacturer.

"We're proud that Red Bull recognizes the importance of green transportation for the environment," said Jim Williams, director, sales and distribution, new products, Navistar. "We need more companies like this to take a stance and add hybrid vehicles to their fleets."

Each truck is estimated to save nearly $4,000 in fuel costs per year. Over the course of a truck's 7- to 10-year life cycle, the four International DuraStar Hybrid units could save up to $160,000 in fuel costs.

A key to the International DuraStar Hybrid's efficiency is the Hybrid Drive Unit, which helps power the diesel engine and leads to less diesel fuel use and fewer emissions. Through the regenerative braking system, the battery in the Hybrid Drive Unit is recharged when the truck's brakes are applied. This energy-saving system makes delivery applications and in-city driving the ideal conditions for these hybrid vehicles.