Warrenville, IL (March 23, 2007) – International Truck and Engine Corporation said its flagship International® ProStar™ class 8 tractor is available with Caterpillar's new C13 engine beginning this summer. Approximately six months ahead of schedule, the Caterpillar C13 rounds out the Cummins and International MaxxForce engine offerings previously announced.

"During the development of the International ProStar, we worked with our three engine partners to develop a truly integrated product – regardless of the customer's engine preference, "said Stephen Gilligan, assistant general manager, heavy vehicles, International Truck and Engine Corporation. "The availability of the CAT C13 is important, as we now have an engine choice to meet every customer need."

The 12.5-liter Caterpillar C13 engine boasts clean-diesel ACERT™ Technology. It features a refined combustion process called Clean Gas Induction and a self-regenerating Diesel Particulate Filter. The new technology meets 2007 EPA regulations while still providing power and reliability.

The Cummins ISX and the International MaxxForce™ 11 and MaxxForce™ 13 engines are also compatible with the International ProStar and all are '07 emissions compliant. New to the ProStar this summer is the Cummins 600HP ISX, the top horsepower rating offered by the Indiana-based engine manufacturer. It is intended for those ProStar customers seeking the higher-performance engine as well as the tractor's fuel-efficient, aerodynamic features. The Cummins 600HP ISX engine is important to drivers who face severe operating difficulties in, say, mountainous regions, or who haul non-diminishing loads.

The International MaxxForce 11 and MaxxForce 13 engines, big bore design, provides up to 1,700 lb.-ft. of torque at 1,000 rpm. The outstanding efficiency and power characteristics of the MaxxForce 11 and MaxxForce 13 – made possible by innovative technologies including a high-pressure common-rail fuel system, twin-series turbochargers with interstage cooler, and Eco-Therm™ heat-management system – set new industry standards for heavy-duty diesel performance, drivability and fuel efficiency.

Accommodating a variety of engines in the International ProStar allows customers to take advantage of the best-in-class fuel economy, unparalleled driver satisfaction, unprecedented uptime and lowest cost of ownership delivered by the vehicle design without sacrificing the confidence afforded by using the engine brand they have grown to trust for their given application.

The new International ProStar (122-inch BBC) began rolling off the assembly line in January after five years in development. The tractor is manufactured at International Truck's Chatham, Ontario, facility, which underwent a major $270 million modernization, including a complete reconfiguration of the assembly line. The 113-inch BBC will be available for MY08.

About International Truck and Engine Corporation
A wholly owned subsidiary of Navistar International Corporation (OTC:NAVZ), International Truck and Engine Corporation is a leading producer of medium trucks, heavy trucks, severe service vehicles, mid-range diesel engines, parts and service. International and its affiliates sell their products, parts and services through a network of nearly 1,000 dealer outlets in the United States, Canada, Brazil and Mexico and from more than 60 dealers in 90 countries throughout the world.