On my current 09 I'm running 325s and did not have to trim a single thing as they are only 32.99" tall. On my old 04 I had BFG 305/65R18s and I had to trim. I only had to trim about 1" off the bottom of the black plastic of the wheel well. I matched the stock curve of the wheel well when I trimmed so nobody would be able to tell the difference.