“Sustainability 360” is the conscious effort on Wal-Mart’s part to increase their contribution in environmentally friendly projects. Keeping this new endeavor in mind, they just took delivery of the Peterbilt Model 386 Hybrid truck. The 386 Hybrid is the first Class 8 hybrid rig that promises to cut fuel costs by $9,000 a year (based on a diesel fuel price of $2.50/gallon). Eaton developed the hybrid system; braking energy is captured and stored in the system’s batteries, this powers the truck’s main electrical system, accessory systems. Plus a generator-motor gives the vehicle the extra boost and helps extend its overall range.

Under certain conditions the rig can even run on only batteries. The Wal-Mart fleet will be continuously evaluated and by Peterbilt till the model’s full production debut in 2009.
Source