The lug nuts that come with the allow wheels have a sheet metal cover.  This cover gets deformed by shops using impact guns and over-tightening the nuts.  They become "swollen" and a 21mm socket will no longer fit.  A socket has to be beat on with a hammer and then the nut won't come out of the socket...
Pep boys has replacement lug nuts for $3 each (part number 99051.1) but I also noticed a solid steel version... no sheet metal cover to swell, just a chuck of chrome plated steel.  It also uses a 21mm socket and the head is ~1/4" longer, the part that fits into the wheel is the same length.  I bought the few they had and they fit a socket much better.  The extra length isn't noticeable when installed.  Part number is 99400.1 and they were $5 each.
			
			
									
						
										
						
