T6.1 Speedo Adjustment for larger wheels

[Desmoben]

Hi, I changed the variant to sort the speedo out on my 6.1 when I put 245/46 r17 BFG A/T's on, I ended up on variant 8 before the speedo was correct.
However...... I have since changed to Cooper Discoverer ATT 225/65 R17 (found the BFG's too heavy and braking wasn't great when fully loaded) and can't change the variant back so stuck with a speedo reading a bit over. Seems a few people have seen this to proceed with caution.....

VW Transporter T6.1 2021 Wheel size coding changes issue

Hiya folks! A customer of mine changed his wheels to 20" and wanted his speedo coded to suit the new wheel size. No issue as this is an available change via the "K-Number" coding in 17 Instrument Cluster and done this many times in older Transporters and Amaroks. Well, turns out there is an...

forums.ross-tech.com

Hi, I changed the variant to sort the speedo out on my 6.1 when I put 245/46 r17 BFG A/T's on, I ended up on variant 8 before the speedo was correct.

However...... I have since changed to Cooper Discoverer ATT 225/65 R17 (found the BFG's too heavy and braking wasn't great when fully loaded) and can't change the variant back so stuck with a speedo reading a bit over. Seems a few people have seen this to proceed with caution.....

VW Transporter T6.1 2021 Wheel size coding changes issue

Hiya folks! A customer of mine changed his wheels to 20" and wanted his speedo coded to suit the new wheel size. No issue as this is an available change via the "K-Number" coding in 17 Instrument Cluster and done this many times in older Transporters and Amaroks. Well, turns out there is an...

forums.ross-tech.com

Hi, did you change both of these values:
00845 wheel circumference average
00845(again) wheel circumference maximum
to variant 8? And did it have any effect on your ACC?

 

[ldm82]

I just changed the one setting (below), no issues with ACC when I did it, everything still works fine for me, just can't change it back to the smaller wheel size.

 

[Desmoben]

I just changed the one setting (below), no issues with ACC when I did it, everything still works fine for me, just can't change it back to the smaller wheel size.

View attachment 133734

Hi, thanks for that - one other question you wrote bfg 245/46 r17’s is that correct?
My bfg’s are 245/65 R17’s

 

[ldm82]

Hi, thanks for that - one other question you wrote bfg 245/46 r17’s is that correct?
My bfg’s are 245/65 R17’s

Fat fingers..... They were 245/65 r17 I had on it.

 

[Desmoben]

Checking again…
Byte 3, bit 0-2 has wheel circumference variant 1 to 8 options available.

Byte19, bit 0-4 has wheel circumferance2 variant 1 to 32 (yes …32??) options available

 

[Desmoben]

I just changed the one setting (below), no issues with ACC when I did it, everything still works fine for me, just can't change it back to the smaller wheel size.

View attachment 133734

Might be interesting to see in advanced measurements what values you have for ide00845 wheel circumference average and ide00845(again) wheel circumference max to see if wheel circumference2 actually refers to either ide00845
Thanks,

 

[ldm82]

Might be interesting to see in advanced measurements what values you have for ide00845 wheel circumference average and ide00845(again) wheel circumference max to see if wheel circumference2 actually refers to either ide00845
Thanks,

I took some screen shots when I did it the first one was standard which was set to 02 Variant 3


This is the output when I changed it to 07 Variant 8, which I can't change back now....


I think the BFG K02 A/T 245/65 r17's have a circumference of 2357mm

 

[Desmoben]

I took some screen shots when I did it the first one was standard which was set to 02 Variant 3
View attachment 133882

This is the output when I changed it to 07 Variant 8, which I can't change back now....
View attachment 133885

I think the BFG K02 A/T 245/65 r17's have a circumference of 2357mm

Right! So it altered the max circumference value by itself.
I wonder did your new code alter the byte19 bit0-4 wheel circumference2 value then also??
Sorry… I really am picking your brains today

 

[ldm82]

Right! So it altered the max circumference value by itself.
I wonder did your new code alter the byte19 bit0-4 wheel circumference2 value then also??
Sorry… I really am picking your brains today

Yes, chaining the variant on byte 3, bits 0-2 updated both average and max circumference.

I don't have a note of the long code from after the change, but iirc nothing else changed on it. I can confirm later though.

 

[Desmoben]

Yes, chaining the variant on byte 3, bits 0-2 updated both average and max circumference.

I don't have a note of the long code from after the change, but iirc nothing else changed on it. I can confirm later though.

I decided to to plough on and make the change to Byte 3, bit 0-2 replacing wheel circumference variant 1 to variant 8. Can confirm that it doesn’t change byte19, bit 0-4 at all.
It accepted the code without issue and no faults showed up until I closed the bonnet and started the engine where I was met with the dreaded ACC not available message… and I thought to myself - Oh F….!
Downhearted I switched off the ignition and hung my head.
2 seconds later I switched it back on and hey presto!.. ACC Available and has been working a treat.. better than before actually. Speedo is now about 4% on the optimistic side but still better than the other way round.

Thanks to Imd82 and Matti mmi

 

[Ragnar]

Hi guys, fresh owner of t6.1 4motion Transporter here, Can someone explain to me if there are any effects by changing you fabric 205/65/16 wheels to for example 225/65/17 ? Saying effects I mean like if it affects systems more than driving itself i've checked https://www.willtheyfit.com/ and it sais -8.73% speed errror, what about cruise control and reports from VW computer onboard, do I have to perform some configuration after the change or will it be just fine and ready to drive ?


PS. I am also wondering, even if 65/17 are ok for t6.1 aren't they just a little to big for this van? I have read some posts on other threads and some people are driving 235/65/17 and the others says it is to much.
I am asking cause I really would like the OZ Rally Raids but as I am aware they are starting from 17" and most of cool agressive tires like Pirelli Scorpion all terain plus rims are starting from 65 height

So I am ending with this 65/17 setup I am wondering about, any tips or corrections ?

 

[Leeabr101]

The 65 should be lowered to compensate for the 16 to 17 inch upgrade. Try using 50-55 in the ratio and see what you get regards speed diff etc.

General Information - Wheels & Tyres

Wheel & Tyre Info - T6 Range These posts are intended for basic information covering the T6 fleet that should hopefully answer lots of initial questions about sizing and fitment If you have any info or think anything should be added that could benefit then please post it below and i will edit...

www.t6forum.com

Alloy Wheel & Tyre Fitment Calculator. Offset, Tyre Stretch and Speedo Error | Will They Fit

Alloy Wheel & tyre fitment calculator - it calculates inset, poke, speedo error, tyre stretch and loads more.

www.willtheyfit.com

The above example now has a speed ratio of 0.91%

 

[Ads_Essex]

T6.1 Speedo Adjustment for larger wheels

I am about to buy a set of Fuel Zephyrs for my T6.1 Shuttle running on 235/65/17 and as far as I am aware no one is yet able to tweak the calibration on the 6.1 software to correct the speedo, so was wondering if anyone has had any experience with this...

www.t6forum.com

Threads merged.

 

[Loz]

Hi guys, fresh owner of t6.1 4motion Transporter here, Can someone explain to me if there are any effects by changing you fabric 205/65/16 wheels to for example 225/65/17 ? Saying effects I mean like if it affects systems more than driving itself i've checked https://www.willtheyfit.com/ and it sais -8.73% speed errror, what about cruise control and reports from VW computer onboard, do I have to perform some configuration after the change or will it be just fine and ready to drive ?


PS. I am also wondering, even if 65/17 are ok for t6.1 aren't they just a little to big for this van? I have read some posts on other threads and some people are driving 235/65/17 and the others says it is to much.
I am asking cause I really would like the OZ Rally Raids but as I am aware they are starting from 17" and most of cool agressive tires like Pirelli Scorpion all terain plus rims are starting from 65 height

So I am ending with this 65/17 setup I am wondering about, any tips or corrections ?

I'm running 235/65/17 PSAT+ on the rally raids and the speedo now matches GPS so no adjustment is necessary.

 

[Ragnar]

I'm running 235/65/17 PSAT+ on the rally raids and the speedo now matches GPS so no adjustment is necessary.

What about ET on rally raids and PSAT+ combo should it be only 35 or others possible ?

 

[SixOneCamper]

I'm running 235/65/17 PSAT+ on the rally raids and the speedo now matches GPS so no adjustment is necessary.

Hi @Loz - I'm going to be running the same tyres on 8J x17 wheels - Is your van lowered at all? If so, by how much and is there any rubbing I should look out for?

 

[Loz]

Hi @Loz - I'm going to be running the same tyres on 8J x17 wheels - Is your van lowered at all? If so, by how much and is there any rubbing I should look out for?

Not lowered, lifted, no rubbing.

 

[jedistar]

I'm running 235/65/17 PSAT+ on the rally raids and the speedo now matches GPS so no adjustment is necessary.

Hello Loz - like many I am looking for AT tyres to fit some Oz Rally Raids when they are supposed to come to Australia early 2022.

I understand from your previous posts that you have used Michelin Latitude Cross 235 55 R17 which are the same diameter (690 mm) as my current factory wheels 215/60R17. Unfortunately the Michelins are not available in Australia - in fact I cannot find a quality AT of that size here.

On this post you mention the Scorpion 235/65/17 which I think have diameter 737 mm.

My question - does this tyre size fit in the spare location without modification? If so I will go for the ATR to keep the noise levels down.

Thank you.

 

[Loz]

Hello Loz - like many I am looking for AT tyres to fit some Oz Rally Raids when they are supposed to come to Australia early 2022.

I understand from your previous posts that you have used Michelin Latitude Cross 235 55 R17 which are the same diameter (690 mm) as my current factory wheels 215/60R17. Unfortunately the Michelins are not available in Australia - in fact I cannot find a quality AT of that size here.

On this post you mention the Scorpion 235/65/17 which I think have diameter 737 mm.

My question - does this tyre size fit in the spare location without modification? If so I will go for the ATR to keep the noise levels down.

Thank you.

I haven't tried to fit one under TBH I kept one of my previous wheels as a spare. You could always deflate it if you carry a compressor.

 

[lolope96]

Not lowered, lifted, no rubbing.View attachment 138144

Hi loz, just about to make the move to new tyres... im on T6 DSG 150hp (remaped to 190..) will this sice afect to my gearing a lot? and how? are you manual?...
Im with 235 55 17... my first option was 235 60 but i love the look of 235 65, and there is more tyres opcions as well...