Search new + high quality used 255 40 R21 Michelin tires online, starting at: $50.87. 255 40R21 Michelin models in stock: 10. All season: 51. Winter: 1. Summer: 14. Run flat: 3. 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!