Bridgestone Firestone North America Tire LLC is renewing a recall on certain SUV spare tires that owners may have overlooked during an original recall five to six years ago, according to regulators.

The National Highway Traffic Safety Admin. says the affected Firestone tires were standard on certain Ford Explorer, Mercury Mountaineer and Mazda Navajo models. These vehicles may have the P235/75R15 Radial ATX and certain P235/75R15 and P255/70R16 Wilderness AT tires made before May 1998. The same classification of tires produced after that date did not have defects, the supplier says.

NHTSA has linked the tires to crashes, including rollovers, caused by blowouts and tread separations, causing 271 deaths and more than 800 injuries through 2005.

Although 6.3 million Bridgestone Firestone tires were recalled in 2000 and 2001, about 200,000 have not been returned to dealers, NHTSA says.

Some vehicles likely still have recalled tires as original spares, which prompted NHTSA and Bridgestone to release a recall reminder to consumers. NHTSA began looking into the issue in June, after being alerted to reports of recent serious incidents tied to recalled tires.

“We may be two to three vehicles removed from the original owner,” says a NHTSA spokesman. “So you may have people who probably aren’t even aware they have a recalled tire.”

Firestone plans to send letters to all current owners notifying them of the recall, which includes a free tire replacement.