Search new + high quality used tires online. Size 315 30 R21 starting at: $30.24. Tires in stock: 272. Available brands: 4 with 22 models. All season: 84. Winter: 20. Summer: 168.. 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!