So, I have always been wondering this noob question, is there any difference in dirt/grass/sand grip between all the slick tires kinds ? If yes then which type of slick tire (R1-R4) is the grippiest on off-road and which one is the slippiest ?

I guess R1 is the grippiest because it's softer, but I don't think you will really notice a big difference between them because they're all pretty slippery.

Quote from Bose321 :

I guess R1 is the grippiest because it's softer, but I don't think you will really notice a big difference between them because they're all pretty slippery.

Well thats weird, because I just tested R1 and R3, however R3 seemed to be a little more stable to me.