T6.1 Speedo Adjustment for larger wheels

With the success of calibrating the speedo for larger wheels on my own T6.1 Transporter, I tried to calibrate the speedo of another T6.1 Transporter.
As is mine, it is a 2023 T6.1. However, it has digital dash instruments and TPMS, where mine has analog dash instruments and no TPMS.

On this T6.1 with digital dash instruments and TPMS, changing wheel circumference variant (17: Instruments, Coding, Byte 3, bit 0-2) has no effect on
17: Instruments, Advanced Measuring Values, IDE00845-MAS03213 Wheel circumference-Average circumference for trip distance, and
IDE00845-MAS03214 Wheel circumference-Maximum circumference for speed.
It is like wheel circumference variant is not connected on this T6.1. It can be set to larger or small without error or effect.

Does anyone know if wheel circumferance2 variant (17: Instruments, Coding, Byte19, bit 0-4) should instead be used on a T6.1 with digital dash instruments?
Is that what wheel circumferance2 variant is for?

VCDS doesn't have a helper for 17: Instruments, Coding, Byte19, so I would like find additional information before experimenting with changes to wheel circumferance2 variant.
Thank you for any and all help.
 
Please share
(1) VCDS Auto-Scans,​
(2) 17-Instruments adaptation maps,​
(3) 17-Instruments blockmaps​
of both vans.
 
Just to add to the collective T6.1 Speedo data, after mine was changed from Wheel circumference variant 1 to Wheel circumference variant 3 it makes the Speedo bang on for 235/55/18’s against GPS.
 
@Loz - Sorry to re-ignite this topic again but I am still struggling to find a definitive answer. I have a T6.1 2020 which has been converted to a camper, when I brought it from new from the converter it came with 18" 255/45 R18's (WolfRace Aero) that always reported about 2/3 under so 30 on speedo 28 on GPS etc. I have recently changed to a set of Fox ADV's 17" with General Grabber AT3 245/65 r17's and now I am seeing the opposite 30 on the speedo and 32/33 GPS and I can see a bigger difference at higher speeds speedo 60 gps 63/64. Can this be corrected successfully on a T6.1? What needs to be changed? Is it still a one way trip ;)
Thanks so much in advance
 
Just came across this when replying to another thread.

For a T6.1 this is the definitive way to do it. Worked on mine no bother. Nothing to do with ‘wheel variant’ but I found the menu which holds the ACTUAL wheel circumference.

See my reply here.


HTH.
 
I assume if you don’t adjust for actual wheel size then the mileage will also be incorrect !
 
I have a T6.1 which had 16" alloys originally and on my sat nav the Speedo was showing around 2mph lower, now I have 20" Navis alloys the sat nav speed is almost exactly the same as the Speedo. I have not made any changes to any settings.
 
Yeah. Lot of people say the 20”s bring it in For me switching up to 17” Navis threw it out more. (However it didn’t manage to sort out my woefully off centre steering wheel from new). Oh the joy ¯\_(ツ)_/¯¯\_(ツ)_/¯
 
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