Firestone FT492 Commercial Truck Tire (14 Ply) The FT491 from Firestone Tire is designed for specialized transport, LTL and truckload service, the Bridgestone FT492 truck trailer tire is SmartWay-verified with a fuel-efficient tread design for low rolling resistance. The wide footprint spreads the load over a larger area, distributing footprint pressure to promote long, smooth wear