I found a set of E39 wheels for a halfway decent price. Can someone tell me what the correct Hubcentric Ring size is for the E39? The internet can't seem to decide if its 74 or 74.1. Are they the same thing? And just to make sure, on the E34 the correct size is 72.56?
Thanks for all the help, as always.
0.1mm is 0.004". Let's call that a manufacturing tolerance 
The offset is more intortant. You can always get the adapters for the hub if needed. I have seen e39 and 7 series wheels on e34s with no issues.
In reply to Keith:
So I'm getting too picky here? I guess I've been doing too many high level math classes where a difference of .001 will give me an answer several hundred off.
In reply to bam2002:
I know that they have the same everything except hub center, rings are needed... I just wasn't sure on the ring size.
You can get the rings on eBay: http://cgi.ebay.com/ebaymotors/Hub-Centric-Rings-fits-BMW-74-1-72-56-E38-E34-740-8... You can get them from the Tire Rack: The part number used to be "A670" (you have to call and ask for them) but my understanding is they've changed the p/n to a new number... "72.56RING". They sell them for about $3/ea. There are other places selling them, those are the two I know about.
