Re: lug bolt radius. OK, I got the M14X1.5 X 27mm part but everyone seems to have their own opinion as to what the proper lug bolt seat radius is for my E550. How does one even measure to determine? Took a bolt out and measured close to 25mm across the widest part of the bolt. Seems like a R13 should work but don't know for sure. Is this something I really need to be concerned about? If someone has the skinny on this, I'd sure like to know. Tnks

Com'on, somebodys got to know this. I've got new wheels comming next week and need to buy matching bolts, new wheels have black centers. Pleeeaaassseeeee...........whine..whine..whine.... .......

Ray
I don't have personal knowledge. Peter@ACGSD said "you need to make sure the wheels have "Ball Seat" and not "Conical Seat" bolt pattern but made no reference to radius."

I'm aware of ball seat bolts in 12mm (R12), 13mm(R13) and 14mm(R14) flavors. There's probablly more but these are the one I would need to consider. I'm really suprised this is such a mystery. Maybe it's a good thing I brought this up if nothing else to set the record straight as to which one we actually need. I'm sure I'm not the only one changing wheels and keep in mind if you do change wheels there's no guarantee which seat has been cut into them. The seat may or may not be the same as OE. As I've mentioned I'm not sure how critical matching the seat radius dimension actually is.

I agree and appreciate you bringing this to our attention.