Tires for TBL

[gaudet]

Hello-
I own a earth force EF4 (Bobcat B300). I am looking for a way to gain more traction. I'd really like to put larger tires on it but I am assuming this is a bad idea for a bunch or reasons. Correct?
Assuming that, I'd like to buy some tire with some very agresive tread on them. They are 12-16.5 size and I can't seam to locate anything locally.
Any help, and addvice would help.
Thanks

 

[gaudet]

Sorry guys. did some googling and think I got a handle on different tires. R1, R2, R3, R4
Now I guess I gotta justdecied what I really need
I still welcome advice