Am I unable to use a tape measure or are these tire shops?

[wildstoats]

Alright guys, feel like I'm losing my mind here. I recently picked up a set of used / refinished wheels. The seller told me they were 16x8 et20 from an e38 740i redrilled to 4x100.

Here's my dilemma, I have been to two different highly recommended tire shops and both have told me that the wheels aren't 16". I measured them myself and they seem to be 16" to me but the shop keeps telling me I have to take an inch off my measurement therefore 15".

Seems unlikely two different shops would be wrong about this so I'm assuming I just don't know how to measure wheels properly or something so I'm hoping you guys can set me straight. The only other thought I had is that perhaps they are metric since 390mm is 15" and some change. If they truly are from an e38 I doubt that's the case though? I'm not sure, not too familiar with those cars.

Here's some pics for reference:

[E30SPDFRK]

They appear to be 16's, post a pic of the face of the wheel so we can identify it.

[wildstoats]

They appear to be 16's, post a pic of the face of the wheel so we can identify it.

[ForcedFirebird]

Take 1" off the 17" measurement you show in the pic and you have 16" (not 1" off each side).

16" tire is measured at the bead, you are measuring the lip.

[wildstoats]

Seemed pretty cut and dry to me not sure why these shops can't figure it out

[DER E30]

They sure measure out to look like 16! Some tire shop people...

[fanboi]

16x8 for sure. BTW, that is an amazing fill and drill. Any idea where that was done at?

[tak7]

that is an amazing fill and drill.

[wildstoats]

Unfortunately I don't have the source of the fill and drill. Did get everything sorted finally and for free to boot. Thanks for the sanity check guys.

[george graves]

You would think if you worked at a tire shop, and looked at rims all day, you could spot wheels/tire size from 10 feet away(I know I can, not 100% accurate, but maybe 99%). Odd.