i have bbs wheels on my 1995 bmw 540i I don't think they're the original wheels so how do i know what size they are
Measure them with a tape measure? End to end across the middle. Probably 15" or 16" is my guess.
This may help, see below, copy and paste. ...
Check the tire for size...
Check the tire for the overall size and usually the wheel width is stamped somewhere on the back of the wheel. You will need to remove a wheel to look.
You could either check the tire size, or measure the diameter of the wheel with a tape measure. Check out the link below and compare your wheels with these original BMW wheels to see if they are original. They likely are original, BMW used BBS to make lots of their wheels through the 90s. http://bmwstylewheels.com/
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