ST. LOUIS - The 2010 MaxxForce 7 V-8 turbodiesel charged into the spotlight this week as Navistar unveiled the new engine at the National Truck Equipment Association's (NTEA) Work Truck Show in St. Louis.

The powerful 6.4-liter MaxxForce 7 includes a new rugged 300-horsepower model that offers medium truck owners outstanding fuel economy and low overall cost of ownership. It combines a 28,000-psi (1,900 bar) high-pressure common-rail fuel system, dual sequential turbocharger system and a high strength compacted graphite iron (CGI) block to power all standard-cab models of International® DuraStar Class 6/7 commercial trucks and the new International TerraStar Class 4/5 commercial trucks. Four available ratings range from 220-300 horsepower and 560-660 lb.-ft. torque. The MaxxForce 7-powered TerraStar will be matched with an Allison 1000 transmission for optimum power output.

"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 pickup 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."

For higher performance and increased durability, an improved air-management strategy includes dual sequential turbochargers and a dual-path exhaust gas recirculation (EGR) cooling system. The smaller, primary turbo responds quickly for immediate take-off at low engine speeds and the larger, secondary turbo provides peak power at higher speeds and on steep grades. Free-wheel turbo design protects against vibrations for improved durability. Dual-path EGR cooling provides cooler EGR in a robust, solidly mounted cast-aluminum housing that suspends critical components to resist vibration and increase reliability. A floating-core EGR cooler design allows for thermal expansion, which significantly extends system performance and life.

The high-pressure common-rail fuel system enables precise fuel dosing, injection timing and optimal combustion. This results in better fuel efficiency, in-cylinder reduction of emissions, and one of the quietest running diesel engines in the industry. The MaxxForce 7 is also compatible with quality B5 to B20 biodiesel blends that meet the industry specification.

The MaxxForce 7's CGI block brings increased durability and lower noise without added weight, compared to typical gray iron. Because CGI has at least 75-percent higher tensile strength, 45 percent higher stiffness and near double the fatigue strength of gray iron, castings don't have to be as thick and heavy in order to achieve the desired structural integrity and durability. At just 1,225 pounds, the 2010 MaxxForce 7 V-8 adds payload and axle capability.

The MaxxForce 7 also offers outstanding unaided cold-starting capability to minus 20 degrees Fahrenheit, with a highly reliable intake-air grid heater so it's ready to go at every turn of the key. Hydraulic roller-cam followers provide a service-free valve train, as valve lash adjustment is not required.

Another key feature of the MaxxForce 7is its chassis-mounted electronic control unit with standard built-in electronic engine protection features which automatically guard against adverse operating conditions.

International brand on-highway commercial vehicles powered by 2010 MaxxForce engines will use MaxxForce Advanced EGR emissions technology. Navistar has pursued its in-cylinder emissions solution path for most of the past decade, with a goal of providing the most customer-friendly powertrain in terms of fuel economy, performance and overall ownership costs. MaxxForce-powered vehicles require only diesel and operate just as commercial vehicles of the recent past. Most importantly, MaxxForce Advanced EGR provides customers with a no-hassle solution that keeps responsibility for emissions compliance with the manufacturer, not the vehicle owner or driver.

MaxxForce-powered International brand vehicles are backed by the largest commercial-truck dealer network in North America with nearly 800 dealer locations and 7,000 service technicians.

 *New model rating for 2010