Search new + high quality used tires online. Size 315 30 R21 starting at: $58.1. Tires in stock: 93. Available brands: 4 with 20 models. All season: 19. Winter: 8. Summer: 66.. 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!