Isuzu Commercial Truck of America unveiled its lineup of 2014 and 2015 model year N-Series diesel models at the Work Truck Show in Indianapolis.

The company also announced that it would extend its 24 Months/60,000 Miles Covered Maintenance Program to all the diesel models sold through June 30.

The allowable frontal area of the popular 12,000-pound GVWR NPR Eco-Max has been increased for the 2014 model year from 6.92 square meters 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 six inches) without application approval from Isuzu. Meanwhile, models equipped with the air deflector can accommodate bodies with inside heights of up to 91 inches with Isuzu application approval.

In addition, the 151-inch wheelbase Eco-Max model offers a dual fuel tank option for the first time. The additional tank is side mounted and carries 33 gallons of fuel. Although pricing has not yet been announced, it is expected to be equivalent to the dual fuel tank option already available on Isuzu NPR-HD, NQR and NRR models.

The NPR Eco-Max and all 2014 and 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 2015 NPR-HD, NQR and NRR models offer new 19.5-inch Bridgestone M895 low rolling resistance tires for improved fuel efficiency without sacrificing strength or durability. 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 new 2015 model year, the 4J 3.0L four-cylinder turbo-diesel engine will adopt the Denso air conditioning compressor already found on the Isuzu 4H 5.2-liter 4 cylinder turbo-diesel engine.

Standard on all 2015 NPR-HD, NQR and NRR models is the same audio system also featured on the 2014 NPR Eco-Max. 

Introduced last October, the Isuzu 24 Months/60,000 Miles Covered Maintenance Program has been extended to apply to all 2014 and 2015 N-Series diesel-powered trucks.

The program includes an initial dry service at 4,000 miles, an A service beginning at 10,000 miles and continuing every 10,000 miles, and an inclusive A/B service at 50,000 miles.

Maintenance services can be obtained at any of Isuzu's 294 dealerships in the U.S.