Two more commercial X-One truck tires from Michelin -- the XDNR2 drive tire and the XTER trailer tire -- have been added to the U.S. Environmental Protection Agency SmartWay's list of verified technologies for tires.

Michelin claims to offer more tire options as certified technologies by the SmartWay program than any other tire maker.

Based upon data provided by tire manufacturers and EPA testing and research, EPA determined that certain tire models can provide a reduction in NOx emissions and an estimated fuel savings of 3 percent or greater, compared to other popular new tires for line haul trucks.

For each axle position, Michelin provides several tire options found on SmartWay's verified technologies list of low rolling resistance tires. They are:

* Steer -- XZA3R and XZA2R;

* Drive -- X-One XDAR, XDAR Energy, XDA3R and XDN2;

* Trailer - X-One XTAR, XTAR Energy, XT-1R and X-One XTE.

Michelin says it has been working to improve mobility by manufacturing tires with low rolling resistance since 1992. Since its introduction in 2000, more than 750,000 X-One tires have been sold. The tire line has saved more than 22 million gallons of fuel and more than 240,000 tons of CO2, and has helped improve trucking fuel economy by up to 10 percent.

A recent four-year, U.S. Department of Energy study showed wide single tires like the X-One increased vehicle fuel economy by 6 to 10 percent.