WARRENVILLE, Ill. (May 7, 2008) Record diesel prices are driving on-highway trucking customers to look for every edge to curb fuel costs, beginning with their choice of truck. Navistar today released definitive results of extensive testing confirming that the International® ProStar™ is the most aerodynamic and fuel-efficient Class 8 truck on the road. 

Recent tests demonstrate that the International ProStar is 7.3 percent more aerodynamic and 7 percent more fuel-efficient than Freightliner’s Cascadia, ProStar’s closest competitor. Overcoming aerodynamic resistance is particularly important for on-highway trucks, as is a fuel-efficient power train.

This margin of leadership translates into substantial savings. Whether operated as part of a company’s fleet of trucks or by an owner-operator, Class 8 trucks rack up a lot of highway miles each year consuming large amounts of diesel fuel. At 120,000 miles a year, each ProStar can save approximately $5,800 annually in fuel over its nearest competitor.

“Clear and decisive fuel-economy leadership is great news for our customers,” said Daniel C. Ustian, Navistar chairman, president and chief executive officer. “The ability to save thousands of dollars in fuel with one truck over the course of a year is extremely significant, especially with the financial pressures placed on truck and fleet owners.”

Navistar is leading the industry in conducting and publishing ongoing testing results so its customers can benefit from fuel-economy savings. Both over-the-road and wind tunnel tests use rigorous TMC and SAE testing procedures, regarded as the highest standards of testing in the transportation industry. Wind tunnel tests were conducted at the National Research Council Institute for Aerospace Research in Canada utilizing SAE J1252 wind tunnel testing practices.

Over-the-Road Testing
Following established Technology & Maintenance Council (TMC) Type IV testing criteria, the trucks were tested on public highways – the most accurate indicator of real-world fuel economy. An International ProStar and the leading competitor, Freightliner Cascadia, each were driven three times over a 444-mile course of public interstate highways. After each run, fuel economy was calculated for both vehicles. Navistar contracted the Transportation Research Center Inc. to conduct the TMC Type IV tests which confirmed ProStar to be 7 percent more fuel-efficient.

These findings support earlier SAE Type III test results regarding ProStar’s fuel efficiency leadership. In October 2007, impartial, head-to-head testing was conducted between ProStar and Cascadia at the Goodyear testing facility. In these tests, ProStar outperformed the Cascadia by 5.7 percent on average fuel consumption.

“The ProStar was best on the test track and is now proven best on the highway,” said Dee Kapur, Navistar Truck Group president. “Clearly, ProStar is the most fuel-efficient Class 8 truck on the market today based on recent over-the-road and wind tunnel testing.”

Wind-Tunnel Testing
ProStar was designed to achieve superior fuel efficiency and aerodynamics. Testing in the wind tunnel to standards established by SAE also confirmed the ProStar is the most aerodynamic Class 8 truck available.

Wind tunnel tests of the International ProStar, the new International LoneStar and leading aero models of truck competitors were recently conducted to determine which has the best aerodynamic performance based on drag coefficient. Aerodynamic drag can consume 50 percent of an engine’s usable horsepower for a truck traveling at 65 mph.

These tests validate the ProStar delivers customers 7.3 percent better aerodynamics than the next best truck tested. Freightliner Cascadia and International LoneStar were essentially tied for second best among models tested.

“Superior aerodynamic design provides an opportunity for owners to save significant amounts of fuel,” said Tom Baughman, general manager, Navistar heavy truck group. “ProStar is clearly the most aerodynamic truck.”

Navistar estimates that the International ProStar’s aerodynamic design can save 1,400 gallons of fuel annually per truck over competitive aero trucks (based on 20,000 gallons of fuel used per year and 7 percent fuel savings; 120,000 miles per year at a 6 mpg baseline). At the national average price of diesel today ($4.15 as of May 7, 2008), saving 1,400 gallons of fuel would save each customer about $5,800 per truck annually.

“International’s aerodynamic superiority represents 25 years of internal research on the major components that affect aerodynamic drag, from hood design to headlamps, wind visors, mirrors, windshield angle and bumpers,” said Ron Schoon, chief aerodynamics engineer, Navistar. “Chassis-skirts that run along the side of the ProStar cab and cover the fuel tank and battery box are designed to reduce drag by as much as nine percent, allowing for a four to five percent improvement in fuel economy.”

“We’ve gone to great lengths to design the International ProStar to be the most fuel-efficient on the road today in order to help customers survive these record-high fuel prices,” said Baughman. “We firmly believe we have the best solution for customers and a series of independent tests validate it – the ProStar can save $5,800 a year in fuel over any other truck available today.”

Additional Fuel-Saving Options
Beyond producing two of the most fuel-efficient Class 8 trucks on the road, Navistar also offers customers other ways to save on fuel costs.

 MaxxPower APU - Operating at 4.2 kW, the MaxxPower APU equates to best-in-class fuel consumption of .18 gallons per hour. It features EPA Tier IV certification and is in the process of acquiring CARB ’08 emissions compliance. Several states currently offer incentives for trucks with idle reduction systems. Production is slated for later this year.

The U.S. Department of Energy estimates trucks use 10 percent of diesel fuel a year while idling. According to DOE figures, the national average for a long-haul sleeper is approximately 1,800 hours per year idling. At a rate of one gallon burned an hour at the national average price of diesel, MaxxPower APU can save nearly $7,600 a year in fuel.

 MaxxForce Engines – MaxxForce 11 and 13 Big Bore engines will be in the marketplace in June, 2008. These engines offer a high-pressure commonrail fuel system and are lighter in weight for further fuel efficiency. Results from fuel economy testing with these new engines will be available in the coming months.

 Maxximum MPG Customer Offer – Customers who spec any 2009 model year International ProStar, LoneStar, TranStar or 9000 Series unit with pre-determined specifications to maximize fuel efficiency, will be eligible to receive a $1,000 voucher for the cost of the truck.

About Navistar
Navistar International Corporation (Other OTC: NAVZ) is a holding company whose wholly owned subsidiaries produce International® brand commercial and military trucks, MaxxForce™ brand diesel engines, IC brand school and commercial buses, and Workhorse brand chassis for motor homes and step vans. It also is a private-label designer and manufacturer of diesel engines for the pickup truck, van and SUV markets. The company also provides truck and diesel engine parts and service. Another affiliate offers financing services. Additional information is available at www.Navistar.com.

Media Contacts:
Heather Street
Navistar
(630) 753-6774
Heather.Street@Navistar.com

Dane Roth
Ketchum
(312) 228-6843
Dane.Roth@ketchum.com