Search new + high quality used tires online. Size 315 40 R21 starting at: $26.89. Tires in stock: 309. Available brands: 8 with 26 models. All season: 248. Winter: 6. Summer: 55.. 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!