[pmcmtnbkr]

So I picked these bmw wheels up last year to mount snow tires on i thought the owner told me he took them off his early 2000 bmw 7 seires. I thought for the giggles of it I would look at finding the cost of a replacement if one where damaged. I found ones that looked like them and appeared to match the part number but it looks like the offset listed on the wheel is 42mm and its an 18x8 wheel. All the ones that I have come across 18x8 is 24 anyone have an idea what bmw model and year these are from

[aerobod]

They are from various 7 series (E65/E66 from 2001 onwards), they do seem to be ET24, based on the part number: https://www.realoem.com/bmw/enUS/par...239&series=E65

[pmcmtnbkr]

Originally Posted by aerobod

They are from various 7 series (E65/E66 from 2001 onwards), they do seem to be ET24, based on the part number: https://www.realoem.com/bmw/enUS/par...239&series=E65

My understanding was the "is" stamp was used to indicate the offset so "is 24" would be a 24mm offset and the "is 42" would be 42mm offset. Am I missing something I wasn't able to find a cross reference of a 7 seires with a 42mm offset in 18x8

[dradernh]

Originally Posted by pmcmtnbkr

My understanding was the "is" stamp was used to indicate the offset so "is 24" would be a 24mm offset and the "is 42" would be 42mm offset. Am I missing something I wasn't able to find a cross reference of a 7 seires with a 42mm offset in 18x8

In the event this turns out to be useful, the 'How to Measure Wheel Backspace or Offset' section on the following page shows how to calculate a wheel's offset:

https://www.rsracing.com/TechWheel.aspx.

[aerobod]

Originally Posted by pmcmtnbkr

My understanding was the "is" stamp was used to indicate the offset so "is 24" would be a 24mm offset and the "is 42" would be 42mm offset. Am I missing something I wasn't able to find a cross reference of a 7 seires with a 42mm offset in 18x8

That would normally be the case, but something is a bit strange about those wheels. Is it certain they are originally off a factory BMW? The castings look a bit rough, as if they could be copies. Here is the back of a Style 93 wheel with the same part number as yours, but with the expected ET24: https://www.ebay.com/itm/Factory-BMW...UAAOSwLDZeqzLp (shown in the second photo).

BMW could have produced some with ET42, but I’ve never seen them reuse the part number for a wheel with a different specification.

Perhaps they used multiple suppliers and someone put the dies for the numbering on the wheel the wrong way around for the “IS” number?

As Dradernh said, best to measure to confirm. Basically put a straight edge across the back of the wheel, measure the distance from rear edge to mounting surface, then from rear edge to the centre of the wheel between the beads, ET is the difference between the two measurements.

[pmcmtnbkr]

Originally Posted by aerobod

That would normally be the case, but something is a bit strange about those wheels. Is it certain they are originally off a factory BMW? The castings look a bit rough, as if they could be copies. Here is the back of a Style 93 wheel with the same part number as yours, but with the expected ET24: https://www.ebay.com/itm/Factory-BMW...UAAOSwLDZeqzLp (shown in the second photo).

BMW could have produced some with ET42, but I’ve never seen them reuse the part number for a wheel with a different specification.

Perhaps they used multiple suppliers and someone put the dies for the numbering on the wheel the wrong way around for the “IS” number?

As Dradernh said, best to measure to confirm. Basically put a straight edge across the back of the wheel, measure the distance from rear edge to mounting surface, then from rear edge to the centre of the wheel between the beads, ET is the difference between the two measurements.

The casting looks rough in the photos it is actually quite smooth I was very lazy when I put them up this spring and didn't give them a good cleaning. Anything is possible as far as what they are since I bought them used. The guy didn't give me any reason to believe they where not factory wheels. I did find one other wheel online Google by image that had the same stamping numbers. I will have to pull one down and measure it to be sure of the offset. This could make things rough if I ever damage one beyond repair

[pmcmtnbkr]

Originally Posted by aerobod

That would normally be the case, but something is a bit strange about those wheels. Is it certain they are originally off a factory BMW? The castings look a bit rough, as if they could be copies. Here is the back of a Style 93 wheel with the same part number as yours, but with the expected ET24: https://www.ebay.com/itm/Factory-BMW...UAAOSwLDZeqzLp (shown in the second photo).

BMW could have produced some with ET42, but I’ve never seen them reuse the part number for a wheel with a different specification.

Perhaps they used multiple suppliers and someone put the dies for the numbering on the wheel the wrong way around for the “IS” number?

As Dradernh said, best to measure to confirm. Basically put a straight edge across the back of the wheel, measure the distance from rear edge to mounting surface, then from rear edge to the centre of the wheel between the beads, ET is the difference between the two measurements.

The casting looks rough in the photos it is actually quite smooth I was very lazy when I put them up this spring and didn't give them a good cleaning. Anything is possible as far as what they are since I bought them used. The guy didn't give me any reason to believe they where not factory wheels. I did find one other wheel online Google by image that had the same stamping numbers. I will have to pull one down and measure it to be sure of the offset. This could make things rough if I ever damage one beyond repair
http://www.allumsimports.com/bmw-17178692

[pmcmtnbkr]

so interestingly enough i have 2 wheels stamped IS24 and 2 wheels stamped IS42. both sets measure at an offset of 24mm. So the only thing I can think is that someone flipped the dies on a batch of these wheels or they are a knockoff wheels. Oh well at least I know what to buy if the need arises