Search new + high quality used tires online. Size 315 40 R21 starting at: $35.06. Tires in stock: 291. Available brands: 4 with 17 models. All season: 270. Winter: 9. Summer: 12.. 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!