I think he's well beyond a socket selection at this point but I agree with Mr. Latos. Just changed the oil and found that the 1/2" 6 point works the best. After getting it off it needed a little dressing up from all the past strippings.......

The last time the oil was changed it was at the dealer. They did'nt tighten the bolt down. I kept getting thin oil strip leaks on the garage floor when I backed out of the garage just going over the kick plate. Didn't happen noticably anytime else. At first I thought it was brake fluid but it wasn't pulling the floor paint up.. A little head scratcher.... Oil level off the stick seemed fine. Finally I dropped the brush cover and had a very slow leak.