Standard on the NPR ECO-MAX is the newest engine in the Isuzu family -- the 4JJ1-TC.

Its high-pressure common-rail fuel injection system wrings the most energy out of every drop of fuel, and its intercooled, variable-geometry turbocharger provides excellent response over the engine's entire RPM range. Together, these features help the 4JJ1-TC produce 150 horsepower and 282 lbs.-ft. of torque.

Despite its spirited performance, this engine is a miser. In fact, the NPR ECO-MAX achieves up to 20% better fuel economy than the previous 12,000-lb. GVWR NPR. Like every Isuzu powerplant, the 4JJ1-TC is a true commercial vehicle engine. Each component has been crafted to reduce maintenance and increase durability.

So it's no surprise that the 4JJ1-TC can be driven up to 10,000 miles between oil changes and has a class-leading B10 durability rating of 310,000 miles -- meaning that 90% of 4JJ1-TC engines will reach that mileage before requiring an overhaul.