OEM 18 ET?

sard · 07-25-2011, 08:20 PM

Anyone know what the OEM 18's wheel spec is? I know it's 18x8.0 What is the ET? Trying to shop for a cheap pair to throw some snow tires on.

andraxxx · 07-26-2011, 05:44 AM

ET is in german "Einpress Tiefe", means rim offset.
For the 18" it's 43mm.

sard · 07-26-2011, 11:50 PM

Thanks a lot =)

Lotus7 · 07-27-2011, 12:28 AM

You may also want to confirm that any aftermarket wheels you consider either have a 72.5 mm hub diameter or are supplied with 72.5 mm adapter rings. BMW uses a "hubcentric" mounting system. Having the correct hub diameter is critical and even other BMW wheels don't all use the same diameter.

sard · 07-27-2011, 01:28 AM

Thanks Lotus7 =)

Harplayr · 07-27-2011, 08:05 AM

So to summarize you should look for:
18x8
43mm offset
72.5mm hub
Bolt Pattern???

Is there any other consideration?

andraxxx · 07-27-2011, 11:25 AM

Bolt Pattern is 5 x 120mm

Lotus7 · 07-27-2011, 01:50 PM

Quote:

Originally Posted by Harplayr

So to summarize you should look for:
18x8
43mm offset
72.5mm hub
Bolt Pattern???

Is there any other consideration?

There are always "other" considerations.

Another important one is that you check the lug bolt engagement with any aftermarket wheel. The M14X1.25 lug bolts come in different lengths. The stock lug bolts on a stock wheel have a MINIMUM of 9.5 turns of engagement (starting the bolt until completely tightened (89 lbs./ft. nominal).

The BMW wheels also use lug bolts with "tapered" seats.

Some aftermarket wheels have thicker hubs and require longer lug bolts. Some aftermarket wheels require bolts with "spherical" seats instead of "tapered".

Be sure that the lug bolt shape matches the wheel "hole" and that you have at least 9.5 turns of each bolt before it stops turning.

It the wheel's machined offset is too shallow and you need to add spacers, you will almost certainly need longer lug bolts.

Harplayr · 07-28-2011, 07:47 AM

That’s a good point.

I have a set of Borbet 17” wheels I used on my old X3 for winter tires.
I took them to the dealer to see if they can be used on the F25.
He put one on, and said it would need longer lug bolts, but other than that it would work.
Even though he indicated it would work, I would feel more comfortable if it was a perfect fit, so I was thinking of selling them and getting a wheel that matched up better.

The problem in researching alternate wheels is that complete specs are often not readily available. How are you to know if it’s a perfect fit before purchasing?

07-25-2011, 08:20 PM	#1
sard Major 235 Rep 1,334 Posts Drives: 2008 M3 Join Date: Oct 2008 Location: Southern California iTrader: (1)	OEM 18 ET? Anyone know what the OEM 18's wheel spec is? I know it's 18x8.0 What is the ET? Trying to shop for a cheap pair to throw some snow tires on. __________________ E92 M3 - DCT - 20" BBS LM-R - KW Clubsport - Akrapovic Exhaust - Powerchip Tune - Arkym Aero Kit - HID Halo
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07-26-2011, 05:44 AM	#2
andraxxx New Member 0 Rep 11 Posts Drives: X3 F25 20d m-sport Join Date: Jul 2011 Location: Germany iTrader: (0)	ET is in german "Einpress Tiefe", means rim offset. For the 18" it's 43mm.
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07-26-2011, 11:50 PM	#3
sard Major 235 Rep 1,334 Posts Drives: 2008 M3 Join Date: Oct 2008 Location: Southern California iTrader: (1)	Thanks a lot =) __________________ E92 M3 - DCT - 20" BBS LM-R - KW Clubsport - Akrapovic Exhaust - Powerchip Tune - Arkym Aero Kit - HID Halo
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07-27-2011, 12:28 AM	#4
Lotus7 Major 66 Rep 1,041 Posts Drives: xxxx Join Date: Dec 2010 Location: xxxx iTrader: (0)	You may also want to confirm that any aftermarket wheels you consider either have a 72.5 mm hub diameter or are supplied with 72.5 mm adapter rings. BMW uses a "hubcentric" mounting system. Having the correct hub diameter is critical and even other BMW wheels don't all use the same diameter.
	Appreciate 0 Quote

07-27-2011, 01:28 AM	#5
sard Major 235 Rep 1,334 Posts Drives: 2008 M3 Join Date: Oct 2008 Location: Southern California iTrader: (1)	Thanks Lotus7 =) __________________ E92 M3 - DCT - 20" BBS LM-R - KW Clubsport - Akrapovic Exhaust - Powerchip Tune - Arkym Aero Kit - HID Halo
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07-27-2011, 08:05 AM	#6
Harplayr Lieutenant 19 Rep 424 Posts Drives: 2011 BMW X3 28i, F25 Join Date: Apr 2011 Location: Chicago iTrader: (0)	So to summarize you should look for: 18x8 43mm offset 72.5mm hub Bolt Pattern??? Is there any other consideration?
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07-27-2011, 11:25 AM	#7
andraxxx New Member 0 Rep 11 Posts Drives: X3 F25 20d m-sport Join Date: Jul 2011 Location: Germany iTrader: (0)	Bolt Pattern is 5 x 120mm
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07-28-2011, 07:47 AM	#9
Harplayr Lieutenant 19 Rep 424 Posts Drives: 2011 BMW X3 28i, F25 Join Date: Apr 2011 Location: Chicago iTrader: (0)	That’s a good point. I have a set of Borbet 17” wheels I used on my old X3 for winter tires. I took them to the dealer to see if they can be used on the F25. He put one on, and said it would need longer lug bolts, but other than that it would work. Even though he indicated it would work, I would feel more comfortable if it was a perfect fit, so I was thinking of selling them and getting a wheel that matched up better. The problem in researching alternate wheels is that complete specs are often not readily available. How are you to know if it’s a perfect fit before purchasing?
	Appreciate 0 Quote