Both models will use the Cummins Westport ISX12 G engine. Mack already offers natural gas-powered Mack TerraPro Low Entry and Mack TerraPro Cabover refuse models.
Like their TerraPro natural gas counterparts, the Mack natural gas-powered Pinnacle and Granite models will feature maintenance-free aftertreatment and require only a three-way catalyst to meet EPA 2010 and CARB emissions standards. Mack's natural gas-powered trucks are available with compressed natural gas or liquefied natural gas fuel systems.
Customer testing for the Pinnacle and Granite models is scheduled to begin this year.
Mack also is investigating other alternative driveline technologies, including high pressure direct injection, which uses a combination of natural gas and a small amount of diesel in the combustion process, and DME (dimethyl ether), which can be produced from natural gas.
In addition, the company continues to move forward on development of diesel-electric hybrid TerraPro models, recently delivering additional Low Entry test units to the New York City Department of Sanitation for evaluation. The Mack diesel-electric hybrid technology provides up to a 30% fuel economy improvement in stop-and-go applications such as refuse, with a corresponding greenhouse gas emissions benefit, the company says.