ISUZU Commercial Truck of America’s new addition to its N-Series line of medium-duty cabover trucks—the NPR-XD, which has a gross vehicle weight rating (GVWR) of 16,000 lbs—is designed to “bridge the gap” between the 14,500-lb NPR-HD and 17,950-lb GVWR NQR.

The new diesel model meets a number of vocational applications and requirements that previously might have required moving from an NPR-HD up to the NQR.

The NPR-XD will be offered in the same cab configurations and wheelbases as the NPR-HD. Its standard cab will be available in wheelbases of 109, 132.5, 150, and 176 inches and will provide a body/payload allowance ranging from 9281 to 9490 lbs, while the crew cab version of the NPR-XD will be available in 150- and 176- inch wheelbases and will provide a body/payload allowance ranging from 8711 to 8779 lbs.

All NPR-XDs will offer 19.5-inch wheels, 225/70R-19.5F 12-ply low-rolling resistance tires, a front gross axle weight rating of 6630 lbs and a rear GAWR of 11,020 lbs. The NPR-XD also comes equipped with the Isuzu 4HK1-TC 5.2-liter turbocharged diesel engine delivering 215 hp and 452 lb-ft of torque and mated to a six-speed automatic transmission.

Standard on every NPR-HD, NQR and NRR is the Isuzu 4HK1-TC engine.

It has a high-pressure common-rail fuel injection system and an intercooled, variable-geometry turbocharger that provides excellent response over the engine’s entire RPM range. Together, these features help the 4JJ1-TC produce 150 horsepower and 282 lb-ft of torque.

The 4HK1-TC is now equipped with electronic high-pressure common-rail direct injection and a water-cooled EGR system to achieve unprecedented performance—210 horsepower for trucks equipped with the automatic transmission, and 190 horsepower for manual-transmission models.
The 4HK1-TC engine can still run up to 10,000 miles between oil changes reducing maintenance costs and downtime and boasts a B10 durability rating of 310,000 miles. And despite the increased power and lower emissions, Isuzu N-Series trucks equipped with the 4HK1-TC engine will achieve approximately 8% better fuel economy than the models they replace.

On the NPR Eco-Max, which features a 12,000-lb GVWR, the frontal area has been increased to 7.4 square meters (7.86 square meters with air deflector). As a result, non-air-deflector equipped models can now handle bodies with inside heights of up to 85 inches (an increase of 6 inches) without application approval from Isuzu. Models equipped with the air deflector can accommodate bodies with inside heights of up to 91 inches with Isuzu application approval.

Also new is a dual fuel tank option on the 151-inch wheelbase model. The additional tank is side-mounted and can carry up to 33 gallons of fuel.

For driver amenities, all new NPR Eco-Max and all 2015 Isuzu N-Series diesel models receive a new AM/FM stereo radio with CD player. The new system includes simplified controls and a standard auxiliary jack input and USB port to accommodate the latest audio technology.

All new 2015 NPR-HD, NQR and NRR models now come with 19.5-inch Bridgestone M895 low-rolling resistance tires for improved fuel efficiency. The M895 tires incorporate stone ejector design that helps protect against stone drilling for enhanced casing durability, closed shoulder design for increased wear life, dual sidewall protector that resists cuts and scrapes, and reinforced steel casing for long life and retreadability.

For the 2015 model year, the 4J 3L 4-cylinder turbo diesel engine will adopt the Denso air conditioning compressor already found on the  Isuzu 4H 5.2L 4-cylinder turbo diesel engine.

Mitch Atari, director of product planning, provided the following upfitter considerations:

  • Diesel coolant line modifications. All emissions on Isuzu diesel trucks MY2011 and newer use engine coolant heat to meet DEF thaw guidelines. No auxiliary heaters may draw heat from the engine coolant for any of these vehicles. Energy used for auxiliary heating may increase DEF thaw times beyond acceptable guidelines. Any auxiliary heaters must include their own self-contained heat source.
  • Emission device modification. Modification may cause calibration issues and void emissions compliance. The DPF/SCR unit cannot be modified or moved. The DEF tank and pump cannot be modified or removed. DEF lines and coolant lines cannot be modified or rerouted.
  • U-bolt placement. Body mounting bracket is installed on the chassis right-hand side.
  •  J-hook. Isuzu frames are not designed for J-hook mounting. This style of mounting could cause frame deformation and will void the frame warranty.
  • Frame modifications. They are allowed if the rules in the body builders’ guide is followed. Incorrect modification procedures may lead to frame failure.
  • Wiring concerns. Harness splicing is not recommended. Remove battery terminal before chassis welding or any electrical modification. Use proper torque for battery cable terminal when reconnecting batteries. Harness routing needs edge protection.
  • Electrical connectors. Weather Pack body builder connectors are located at the end of the frame for improved body mounting and fewer electrical problems.
  • Tail lamp harness connectors. The connectors that match the frame tail and stop lamp harness can be ordered through Isuzu dealers. Chassis harness side part number: 897364-5300. Tail lamp side part number: 897-364-5310. ♦

Find the NTEA Truck Product Conference Report archive with articles from 2012 to present