Search new + high quality used 225 45 R18 Firestone tires online, starting at: $56.36. 225 45R18 Firestone models in stock: 5. All season: 14. Winter: 2. Summer: 2.. Selling all used tires at discount costs. All used tires go through 2 layers of inspection on specialized equipment. One year warranty + free shipping on all inventory ;) Happy shopping!