SPRINGFIELD, Ohio, April 22, 2008 American Electric Power (NYSE: AEP), one of the largest electric utilities in the United States, is expanding its green efforts to include more hybrid trucks. On Earth Day, at Navistar, Inc.’s Springfield, Ohio, Assembly Plant, AEP is announcing that it has ordered its largest number of hybrid trucks to date – 18 International® DuraStar™ Hybrid diesel trucks. 

The addition of 18 International DuraStar Hybrids will bring the total number of hybrid utility trucks in AEP’s fleet to 22 – giving AEP the largest fleet of diesel hybrid utility trucks in the country

International DuraStar Hybrid trucks have the proven capability to provide dramatic fuel savings of nearly 60 percent in utility-type applications when the engine can be shut off, but electric power still operates the vehicle. Diesel emissions are completely eliminated when the hybrid truck operates equipment (like overhead utility booms) solely on the truck’s battery power, instead of requiring the engine to run.

“AEP has experienced great results from our first four International hybrid trucks,” said Helen Murray, president and chief operating officer for Indiana Michigan Power (I&M), an operating company subsidiary of AEP. “We are proud to expand our use of hybrid trucks,” said Murray. “It’s a good business decision, and the right thing to do for the environment.”

The additional 18 hybrid units are expected to be delivered this summer, of which 13 will operate in Indiana Michigan Power’s fleet. AEP has nearly 1,500 International trucks in its fleet.

“The hybrid combination of the diesel engine and electric battery provides a number of advantages for companies like AEP,” said Jim Williams, director of sales and distribution, new products, Navistar. “We commend AEP for exhibiting leadership with this new technology. The ability to cut diesel fuel use in half, reduce emissions, reduce greenhouse gases and reduce engine wear not only is a smart environmental decision, it’s a smart business decision as well.”

The Hybrid Truck Users Forum estimates that 1,000-1,500 gallons of fuel can be saved per utility truck annually. At today’s high diesel prices, that equates to a savings of $4,000-$6,000 in fuel per truck annually. It also results in annual greenhouse gas reductions of 11 to 16.5 tons of carbon dioxide per unit. AEP expects to save $72,000-$108,000 in fuel costs and eliminate 200 to 300 tons of carbon dioxide emissions over a one-year period with this order of 18 trucks.

International DuraStar Hybrid trucks employ a parallel-type, diesel-electric hybrid architecture that is supplied by Eaton Corporation. It incorporates an electric motor/generator between the output of an automated clutch and input of the automated transmission. The system recovers energy normally lost during braking and stores the energy in batteries. The hybrid-electric system recovers energy during braking, and can add power back into the driveline during start and acceleration.

This capability makes the truck more efficient in standard driving, particularly in city and stop-and-go driving. When the truck reaches a work site, the hybrid system can power the hydraulic pump that operates the aerial device and the tools for up to two hours without the engine running. It is this ability to shut the engine down at work sites that helps the truck cut fuel use so significantly. The engine-off option during worksite operations further reduces noise, emissions and fuel costs.

Navistar received the 2007 Blue Sky Award from WestStart-CALSTART for its contributions to the commercial development of diesel-hybrid technology. This preeminent award is presented each year by WestStart-CALSTART, the nation's leading advanced transportation technology industry organization working to support and accelerate the growth of companies developing clean and energy-efficient transportation technologies. Shortly after that award, Navistar announced in November 2007 that is was the first commercial truck company to enter line production of hybrid trucks. The trucks are built at the company’s Springfield, Ohio, plant. Customers can learn more about hybrid trucks at www.InternationalTrucks.com/hybrid.

About AEP
American Electric Power is one of the largest electric utilities in the United States, delivering electricity to more than 5 million customers in 11 states. AEP ranks among the nation’s largest generators of electricity, owning nearly 38,000 megawatts of generating capacity in the U.S. AEP also owns the nation’s largest electricity transmission system, a nearly 39,000-mile network that includes more 765 kilovolt extra-high voltage transmission lines than all other U.S. transmission systems combined. AEP’s transmission system directly or indirectly serves about 10 percent of the electricity demand in the Eastern Interconnection, the interconnected transmission system that covers 38 eastern and central U.S. states and eastern Canada, and approximately 11 percent of the electricity demand in ERCOT, the transmission system that covers much of Texas. AEP’s utility units operate as AEP Ohio, AEP Texas, Appalachian Power (in Virginia and West Virginia), AEP Appalachian Power (in Tennessee), Indiana Michigan Power, Kentucky Power, Public Service Company of Oklahoma, and Southwestern Electric Power Company (in Arkansas, Louisiana and east Texas). AEP’s headquarters are in Columbus, Ohio.

About Eaton
Eaton Corporation is a diversified industrial manufacturer with 2007 sales of $13.0 billion. Eaton is a global leader in electrical systems and components for power quality, distribution and control; hydraulics components, systems and services for industrial and mobile equipment; hydraulics, fuel and pneumatic systems for commercial and military aircraft; intelligent truck drivetrain systems for safety and fuel economy; and automotive engine air management systems, powertrain solutions and specialty controls for performance, fuel economy and safety. Eaton has 79,000 employees and sells products to customers in more than 150 countries.

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:
Mark Johnson
Navistar
(630) 753-3518
Mark.Johnson@Navistar.com  

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