Factory Wheels 666 vs 437

Garth2079 · 08-26-2023, 02:00 AM

Hi all,

The first owner of my 2016 M3 Competition apparently didn't like the standard 666 wheels, and paid the dealer to swap them for 437 wheels. I would have thought the dealer should be paying him, but hey.

When I am driving at an indicated 100kph, my GPS shows an actual 93kph. This percentage difference is consistent up and down the speed range. I'm familiar with BMW's over-cautious speed correction, but I have done the maths and the circumference of the 437 (19") wheels (with stock tyres) is only 98% of the 666 (20") wheels' (with stock tyres) circumference. If I travelled 1km with the 20" wheels, the rear wheels would turn 469 times. With the 19" wheels, it would be 477 times. That's a difference of about 2%, which suggests the different wheels are making the already conservative speedo even further out.

I am aware of the FDL coding to remove the built-in adjustment, which might well help. I'm also aware that nobody has found the FDL codes to adjust the speedo beyond removing the standard correction.

However, BMW sell plenty of identical cars with different wheels, and those wheels and tyres each have a different circumference. It occurred to me that BMW list the factory wheels as part of the VO - for instance 2VZ = 437 wheels. My guess is that the wheel circumferences are set via the VO. Unfortunately I'm not smart enough to know how to check this, although I think I have read that some people can run a "what if?" type preview that shows them the actual FDL coding created by a VO change before it is applied.

If anyone knows how to do that, I would be very interested to know the coding differences between 2VZ (437 wheels) and 21T (666 wheels) to determine if the speedo is indeed calibrated to deal with the 2% difference in circumference.

Also, if anyone knows how to find the VO for 763 wheels (which seem to have shipped with some F87 M2 Competitions), I'd love to hear it since that what I now have on the car. I have tried searching the cars currently listed online and looking up their VINs but without success since most seem to ship with 788 wheels from the factory and hence have a different VO (edit: found it - 1TN).

Thanks in advance.

Garth2079 · 08-26-2023, 03:11 AM

I found the option code in this thread, along with lots of other wheels: https://f87.bimmerpost.com/forums/sh...33&postcount=3

Still keen to hear if changing the VO will make changes to the speedo.

Garth2079 · 08-27-2023, 02:26 AM

For completeness, it was quoted in a BMW SIB that the speedo can't be calibrated. Presumably it's a one-time thing in the factory.

It is possible to disable the ~3% correction:

KOMBI
3000
BC_V_KORREKTUR active > nicht_activ

Changing that setting affects both the speedo needle and Heads-up digital speed, so they both still read the same.

At an indicated 60kph my car is now travelling at 57kph, instead of 53/54kph. That's near enough for me. I'll test the ODO on a longer journey but my guess is it will be recording 102km for every actual 100km travelled. So be it.

The moral of the story... order your next BMW with 17" wheels, then swap them for 19" or 20". The speedo will be correct and you'll only record 95km for every 100km travelled.

Thanks go out to the usual gentleman for offering your thoughts. You know who you are!

shawnsheridan · 08-27-2023, 10:49 AM

Quote:

Originally Posted by Garth2079

For completeness, it was quoted in a BMW SIB that the speedo can't be calibrated. Presumably it's a one-time thing in the factory.

It is possible to disable the ~3% correction:

KOMBI
3000
BC_V_KORREKTUR active > nicht_activ

Changing that setting affects both the speedo needle and Heads-up digital speed, so they both still read the same.

At an indicated 60kph my car is now travelling at 57kph, instead of 53/54kph. That's near enough for me. I'll test the ODO on a longer journey but my guess is it will be recording 102km for every actual 100km travelled. So be it.

The moral of the story... order your next BMW with 17" wheels, then swap them for 19" or 20". The speedo will be correct and you'll only record 95km for every 100km travelled.

Thanks go out to the usual gentleman for offering your thoughts. You know who you are!

08-26-2023, 02:00 AM	#1
Garth2079 New Member 11 Rep 27 Posts Drives: 2016 F80 Comp Manual Join Date: Oct 2016 Location: Sydney iTrader: (0)	Factory Wheels 666 vs 437 - VO Coding Hi all, The first owner of my 2016 M3 Competition apparently didn't like the standard 666 wheels, and paid the dealer to swap them for 437 wheels. I would have thought the dealer should be paying him, but hey. When I am driving at an indicated 100kph, my GPS shows an actual 93kph. This percentage difference is consistent up and down the speed range. I'm familiar with BMW's over-cautious speed correction, but I have done the maths and the circumference of the 437 (19") wheels (with stock tyres) is only 98% of the 666 (20") wheels' (with stock tyres) circumference. If I travelled 1km with the 20" wheels, the rear wheels would turn 469 times. With the 19" wheels, it would be 477 times. That's a difference of about 2%, which suggests the different wheels are making the already conservative speedo even further out. I am aware of the FDL coding to remove the built-in adjustment, which might well help. I'm also aware that nobody has found the FDL codes to adjust the speedo beyond removing the standard correction. However, BMW sell plenty of identical cars with different wheels, and those wheels and tyres each have a different circumference. It occurred to me that BMW list the factory wheels as part of the VO - for instance 2VZ = 437 wheels. My guess is that the wheel circumferences are set via the VO. Unfortunately I'm not smart enough to know how to check this, although I think I have read that some people can run a "what if?" type preview that shows them the actual FDL coding created by a VO change before it is applied. If anyone knows how to do that, I would be very interested to know the coding differences between 2VZ (437 wheels) and 21T (666 wheels) to determine if the speedo is indeed calibrated to deal with the 2% difference in circumference. Also, if anyone knows how to find the VO for 763 wheels (which seem to have shipped with some F87 M2 Competitions), I'd love to hear it since that what I now have on the car. I have tried searching the cars currently listed online and looking up their VINs but without success since most seem to ship with 788 wheels from the factory and hence have a different VO (edit: found it - 1TN). Thanks in advance. Last edited by Garth2079; 08-26-2023 at 07:40 AM..
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08-26-2023, 03:11 AM	#2
Garth2079 New Member 11 Rep 27 Posts Drives: 2016 F80 Comp Manual Join Date: Oct 2016 Location: Sydney iTrader: (0)	I found the option code in this thread, along with lots of other wheels: https://f87.bimmerpost.com/forums/sh...33&postcount=3 Still keen to hear if changing the VO will make changes to the speedo.
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08-27-2023, 02:26 AM	#3
Garth2079 New Member 11 Rep 27 Posts Drives: 2016 F80 Comp Manual Join Date: Oct 2016 Location: Sydney iTrader: (0)	For completeness, it was quoted in a BMW SIB that the speedo can't be calibrated. Presumably it's a one-time thing in the factory. It is possible to disable the ~3% correction: KOMBI 3000 BC_V_KORREKTUR active > nicht_activ Changing that setting affects both the speedo needle and Heads-up digital speed, so they both still read the same. At an indicated 60kph my car is now travelling at 57kph, instead of 53/54kph. That's near enough for me. I'll test the ODO on a longer journey but my guess is it will be recording 102km for every actual 100km travelled. So be it. The moral of the story... order your next BMW with 17" wheels, then swap them for 19" or 20". The speedo will be correct and you'll only record 95km for every 100km travelled. Thanks go out to the usual gentleman for offering your thoughts. You know who you are!
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