Search new + high quality used tires online. Size 315 40 R21 starting at: $53.78. Tires in stock: 114. Available brands: 6 with 17 models. All season: 93. Winter: 1. Summer: 20.. 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!