Well we knew it was just a matter of time until Peterbilt stepped up to the plate with a Hybrid Truck and the engineers at Eaton Corporation their  partner in the new design were holding nothing back. In fact this new truck is not only breaking sales records - selling like hotcakes, but it is delivering incredible fuel efficiency and savings, as well as power. Just what the trucking company customers ordered and a few municipalities and utility companies too.
Peterbilt (Model 335) has introduced their Hybrid Medium Duty Truck and it's main market is for Utility Companies and Cities, which are leading by example. Peterbilt's customers have requested a Hybrid Unit for PR and cost savings. The Model 335 has a 6.7 Liter PX-6 PACCAR Diesel hybrid motor, which uses Eaton Corporation Technologies.
It boasts a 28 to 40% fuel savings using hydraulic Hybrid assist which means that it also works great for work trucks which use a PTO - Power Take Off unit to power up boom or other equipment.
Peterbilt also makes a Model 320 which has a Hydraulic Launch Assist system and it is a Class 8 Truck. The Model 320 collects a portion of the heat from the brakes in hydraulic fluid, which is used later to help assist in acceleration, when the most amount of fuel is typically used. The scheme works very well actually and is an example of great innovation and superb engineering agrees the T-5 Group (The Truck Think Tank Team). | 
