ST. LOUIS, Mo. — Navistar has unveiled a new International MaxxForce 7, 6.4-litre V-8 turbdiesel engine to power medium-duty work trucks.

The engine includes a new 300 hp model the company claims delivers outstanding fuel economy and low cost of ownership. It features a 28,000 psi high-pressure common-rail fuel system, dual sequential turbo system and high-strength, low-weight compacted graphite iron (CGI) engine block.

The new engine is available with International DuraStar Class 6/7 and new TerraStar Class 4/5 trucks, Navistar announced.

Horsepower options range from 220-300 with 560-660 lb.-ft. of torque.

“This V-8 marks one of the most significant product upgrades in our history as we met the market’s challenge for big power from an efficient, reliable and durable platform,” said Jim Hebe, Navistar senior vice-president, North American sales operations. “Customers whose business involves pick-up and delivery, towing and recovery, landscape or emergency vehicles such as ambulances, will find the MaxxForce 7 to be the perfect fit for their operations with true commercial vehicle power, durability and capability.”

Navistar says its new engine boasts quiet operation thanks to the CGI block coupled with a fuel system that allows for precise fuel dosing and injection timing. The engine is also lightweight, coming in at 1,225 lbs, which the company claims will allow for greater payload.

As with all other Navistar engines, the MaxxForce 7 will be EPA2010-compliant without using selective catalytic reduction (SCR) technology.