* What's covered: all new radial tires for passenger cars, multipurpose passenger vehicles, trucks, buses and trailers weighing under 10,000 pounds; all radial P-metric light truck tires with Load Ranges C, D or E (the first time LT tires have been covered).
* What's exempt: All bias-ply tires, small trailer, retreaded and non-pneumatic spare tires.
* More stringent testing requirements for limited-production, snow and deep-tread radial tires.
* High speed and endurance test stricter than the old rule.
* Low inflation pressure test.
* NHTSA's estimated cost to the tire industry: between $3.6 million and $31.6 million annually.