I have a question about Tire Speed Rating. What is a better ratio for a Rover? 109S or say 108/104S ? I am not sure what the dash behind the 108 is for after the last example? Could someone better explain this to me? I understand for the most part that S and R stand for how fast you can go however I am still unsure of why some tires have for example the 108/104. Thanks in advance for helping me with this conundrum!