Navistar, the long-time holdout in adopting SCR urea aftertreatment technology on its trucks to meet federal NOx emissions standards, has now adopted the industry-wide standard and is starting to ship vocational models equipped with its Selective Catalyst Reduction (SCR) technology to commercial buyers. Models equipped with the 9 and 10L engines deliver power output of between 275-330 hp and 860-950 lb-ft of torque on the DuraStar models and between 275 to 350 hp and 860-1,150 lb-ft on the WorkStar models. Navistar claims a fuel efficiency improvement of up to 8 percent compared to predecessor models.
Extreme environment testing was conducted on these engines in high-altitude and extreme cold and hot environments, including Alaska, Colorado, and Arizona. Tests included rigorous vocational duty cycles designed to replicate real-world use. Vocational applications for the DuraStar and WorkStar include garbage trucks, sewer pumpers, and utility service trucks. The trucks are also equipped with Navistar’s exclusive Diamond Logic electrical system, designed to aid operator efficiency and prevent equipment damage.
The International ProStar equipped with the Cummins ISX15 engine and the TerraStar 4x4 were named the 2014 heavy-duty and medium-duty commercial trucks of the year by the American Truck Dealers association.