Upsizing Tyres things to know

[ranagazoo]

So I've recently got myself a VW transporter t6.1 Highline and have a few questions regarding tyre size.

I've researched most things the best I can but for other things I can't seem to find a definite answer so I apologise if there is a thread already present on the forum but I really appreciate the expertise of the people here should you help me and not shoot me down.

I currently have the standard 16" fitted to my van and I think they look terrible so I want to get some 20".

I've looked on the Navis website and found the alloys and wheels I like the look of. They recommended 265/40/20 for ride comfort etc so think I'm sorted with wheel choice. I'm wary of the load rating etc so these are all good as a choice to go with as they meet the criteria. However I have a few concerns and questions still.

With bigger wheels does it affect parts such as gearbox and is there anything else that needs upgraded alongside the wheels?

How badly will the speedometer be affected and implications with this? Can it be easily recalibrated?

Anything else I should be worried about or wary of from your experience?

Thanks in advance.

 

[DaveD]

Welcome to the forum!
All of the answers to your questions are here, have a browse through some of these threads;

Search results for query: 20

www.t6forum.com

Enjoy your new van!

 

[Linoleum Bonypart]

There’s a website which I can’t find shows you what wheel/tyre change looks like and how it affects Speedo
18s are best of both 20s are a bit extreme and don’t ride as well

 

[JOG]

Hi and welcome to the forum.

The first thing to consider is what you want to achieve. If it is to “fill” wheel arch for aesthetic reasons, there is more than wheel/tyre size to consider. If it is a comfort consideration, then size and suspension matter. What you will be using the van for is the biggest consideration: a work horse that carries load, a daily driver, a future conversion to camper etc.

Measure from the wheel centre to wheel arch all round - is the van sitting properly? If not, that needs sorting first.

Wheel-wise, anything less than 17” rims is pants as it doesn’t allow you improve your brakes - another massive subject in itself! Overall rolling circumference does impact speedo accuracy and gear train load, so don’t depart from the norm too much.

I don’t know where in the country you are but there are many respected traders on this forum who can help you. @Dav-Tec @CRS Performance @The Van Cave

 

[JOG]

There’s a website which I can’t find shows you what wheel/tyre change looks like and how it affects Speedo
18s are best of both 20s are a bit extreme and don’t ride as well

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 Van Cave]

So I've recently got myself a VW transporter t6.1 Highline and have a few questions regarding tyre size.

I've researched most things the best I can but for other things I can't seem to find a definite answer so I apologise if there is a thread already present on the forum but I really appreciate the expertise of the people here should you help me and not shoot me down.

I currently have the standard 16" fitted to my van and I think they look terrible so I want to get some 20".

I've looked on the Navis website and found the alloys and wheels I like the look of. They recommended 265/40/20 for ride comfort etc so think I'm sorted with wheel choice. I'm wary of the load rating etc so these are all good as a choice to go with as they meet the criteria. However I have a few concerns and questions still.

With bigger wheels does it affect parts such as gearbox and is there anything else that needs upgraded alongside the wheels?

How badly will the speedometer be affected and implications with this? Can it be easily recalibrated?

Anything else I should be worried about or wary of from your experience?

Thanks in advance.

The 265/40 is a good choice overall and won't affect the speedo enough that you need to worry about it being recalibrated. Recalibrating the speedo can be done via VCDS, although it can't be changed back again on the T6.1, but you don't need to worry. Your speedo will over read slightly from factory and the relatively small difference in rolling radius between your original size and the 265/40 will mean that the speedo will be very close to reading your actual speed with the new wheels and tyres.

 

[Vinyl1210]

Hi. I have 17’s Navis off THQ and very pleased. Re speedo, yes it will be affected. (I have T6.1 HL too)

There are threads on here I’ve read relating to changing ‘Wheel Circumference Variant’ with varying success as to how it affects Speedo. (As I say this is for a T6.1).

Once you have your wheels and tyres go onto “will they fit.com” and input your wheel and tyre details to obtain rolling circumference in mm. You’ll need a diagnostic tech or such to plug into the OBD with a ‘Full OEM compatible Diagnostic Programme’. My mate owns a Bosch Service Centre so has just this. I’m not sure if basic VCDS will cut it??? Others will confirm or deny. Access the following menu. (We wrote it down so we could easily find it again!!)

‘PARK STEER ASSIST’

Within this menu is the ACTUAL wheel and tyre rolling circumference. (Mine was 2150 mm from factory with standard 16” Alloys).
Make a note of your original number incase you put back to stock.

Input new Rolling Circumference as found above.

Save and exit.

Hey presto sorted. (I then checked with GPS and was slightly out by a couple of mph so I tweaked again by a few mm to get spot on )

Can easily be changed depending what wheels you have throughout the year. (Thinking winter tyres etc).

HTH.

 

[Swamperise]

Hi. I have 17’s Navis off THQ and very pleased. Re speedo, yes it will be affected. (I have T6.1 HL too)

There are threads on here I’ve read relating to changing ‘Wheel Circumference Variant’ with varying success as to how it affects Speedo. (As I say this is for a T6.1).

Once you have your wheels and tyres go onto “will they fit.com” and input your wheel and tyre details to obtain rolling circumference in mm. You’ll need a diagnostic tech or such to plug into the OBD with a ‘Full OEM compatible Diagnostic Programme’. My mate owns a Bosch Service Centre so has just this. I’m not sure if basic VCDS will cut it??? Others will confirm or deny. Access the following menu. (We wrote it down so we could easily find it again!!)

‘PARK STEER ASSIST’

Within this menu is the ACTUAL wheel and tyre rolling circumference. (Mine was 2150 mm from factory with standard 16” Alloys).
Make a note of your original number incase you put back to stock.

Input new Rolling Circumference as found above.

Save and exit.

Hey presto sorted. (I then checked with GPS and was slightly out by a couple of mph so I tweaked again by a few mm to get spot on )

Can easily be changed depending what wheels you have throughout the year. (Thinking winter tyres etc).

HTH.

This sounds promising after reading so many discussions on how the 6.1 setting for changing the wheel circumference is a one-way function in VCDS.

So to confirm changing the wheel circumference has nothing to do with "Wheel Circumference Variant" in VCDS, and what you should really be changing is the "Park Steer Assist" values?

I am considering changing up from OEM 17" alloys (17" 7J with 215/60 R17 tyres, circumference 2167mm) to a swamper look. still 17" rim size but 8J width instead of OEM 7J.

The BFG's KO2's have a circumference of 2357mm which would result in a reduction of speedo reading of about 8%, so at 60mph the speedo would read 55 mph.

Is the value you change in "Park Steer Assist" simply one that would read 2167mm (OEM) to 2357mm (BFG)? Will amending this setting carry through to all aspects of the vehicle that require a correct circumference setting, i.e. your speedo speed, ODO/Trip mileage, MPG estimation, ABS, Adaptive cruise control etc. etc....?

Do you have a full step-by-step process of how this was changed through the diagnostic tool?

 

[Vinyl1210]

As per my post really. Go into Park Steer Assist and change the wheel circumference. If your wheels are 2357 then that’s what you put. It should change all applicable systems.
I cannot tell you step by step as my mate who is a VW Master Tech did it with his laptop with VW approved Bosch Diagnostic program, but just watching him it was a two minute job. Totally reversible if required. (However menu location as my post is correct).
And…..yes I’ve heard loads of horror stories of people with VCDS dabbling with the wheel variants only to find they’ve bu&&erred it and it’s a one shot deal. (Hence why I went to someone who knows what he’s doing).
HTH

 

[Skyliner33]

As per my post really. Go into Park Steer Assist and change the wheel circumference. If your wheels are 2357 then that’s what you put. It should change all applicable systems.
I cannot tell you step by step as my mate who is a VW Master Tech did it with his laptop with VW approved Bosch Diagnostic program, but just watching him it was a two minute job. Totally reversible if required. (However menu location as my post is correct).
And…..yes I’ve heard loads of horror stories of people with VCDS dabbling with the wheel variants only to find they’ve bu&&erred it and it’s a one shot deal. (Hence why I went to someone who knows what he’s doing).
HTH

This sounds interesting. Would your VW Master Tech care to share any further details? I am sure it would be helpful to a lot of the forum members. Even if it can’t be done with vcds there are members on here who have ODIs systems (and maybe others) who could carry out this adjustment.

 

[Vinyl1210]

It’s as simple as it sounds. Those who’ve got ODI’s or an appropriate program will easily find the ‘Park Steer Assist’ menu and be able to click on it. Then it really is as simple as changing the value on the wheel circumference. Hey presto.

 

[Vinyl1210]

I don’t think there’s any ‘dark art’ to it TBH, just that VCDS can’t (AFAIA) access that menu so this is why people perhaps sometimes try and tweak the wheel type settings, which on a T6.1 is irreversible. (Again AFAI understand it). HTH

 

[Swamperise]

Thank you for your quick response.

Any VCDS users out there who might be able to confirm whether the "Park Steer Assist" menu is/isn't available through VCDS, and if the value is visible whether can be changed or not?

Where is your tech guy based, could you enquire what he would charge to do this modification if all DIY options come to nothing?

 

[Paul Sussex]

There’s a website which I can’t find shows you what wheel/tyre change looks like and how it affects Speedo
18s are best of both 20s are a bit extreme and don’t ride as well

This one allows you to compare sizes:

Tire Size Comparison

Tire size comparison the easy way. Use our tire size comparison calculator to compare diameter, width, sidewall, circumference and revolutions per mile.

tiresize.com

 

[Paul Sussex]

I don’t know if this is the case for sure but you might want to think about it.

If the speedo is wrong then the milometer might be too.

This could affect fuel calculations, service interval indicators and overall number of driven miles recorded (so not sure what happens if you sell in the future).

 

[Vinyl1210]

I don’t know if this is the case for sure but you might want to think about it.

If the speedo is wrong then the milometer might be too.

This could affect fuel calculations, service interval indicators and overall number of driven miles recorded (so not sure what happens if you sell in the future).

Yes Paul, this is how I (we - my mate) understand it, hence why I wanted it changed. More so for the Speedo but it does affect other parameters although TBF not by a massive amount. (Someone I’m sure will work it out) but we are talking a gradual discrepancy over the lifetime of the van.

Thank you for your quick response.
Where is your tech guy based, could you enquire what he would charge to do this modification if all DIY options come to nothing?

He’s based in Andover, Hampshire. I’m seeing him later this week so I’ll ask for some more details regards Operating System’Program required blah blah. (it’s equivalent to Main Dealer I do know that much). Re: a charge, I’m sure he’d do it for very little. (And he’s an VW nut!!) After all it’s such a quick job. If I get details I’ll post as any Service Outlet with the right program (main dealer, diagnostic specialist etc) should be able to access it. I’ll also ask him if he knows if VCDS had the capability to change it too. (It’s not like he’s managed to crack the enigma code or anything like that, or he’s being secretive, it’s just he knows his way round the systems).

The main reason he first looked for me, when I chatted about the issues people were having with VCDS and changing the wheel variant only to find they couldn’t change it back, (which he was aware of as it alters the main ‘operating system’ if you like, (best analogy I can give) was he knows it’s common practice on the continent (in some countries) to change the wheels and sizes for harsh winter conditions then change back in the summer (Thinking France, Switzerland etc) so he said ‘you must be able to alter it like for like, I’ll just have to find it’. Hey presto, 5 minutes later he’s got it.

Will post with update in due course.

Cheers.

 

[Swamperise]

Th

Yes Paul, this is how I (we - my mate) understand it, hence why I wanted it changed. More so for the Speedo but it does affect other parameters although TBF not by a massive amount. (Someone I’m sure will work it out) but we are talking a gradual discrepancy over the lifetime of the van.



He’s based in Andover, Hampshire. I’m seeing him later this week so I’ll ask for some more details regards Operating System’Program required blah blah. (it’s equivalent to Main Dealer I do know that much). Re: a charge, I’m sure he’d do it for very little. (And he’s an VW nut!!) After all it’s such a quick job. If I get details I’ll post as any Service Outlet with the right program (main dealer, diagnostic specialist etc) should be able to access it. I’ll also ask him if he knows if VCDS had the capability to change it too. (It’s not like he’s managed to crack the enigma code or anything like that, or he’s being secretive, it’s just he knows his way round the systems).

The main reason he first looked for me, when I chatted about the issues people were having with VCDS and changing the wheel variant only to find they couldn’t change it back, (which he was aware of as it alters the main ‘operating system’ if you like, (best analogy I can give) was he knows it’s common practice on the continent (in some countries) to change the wheels and sizes for harsh winter conditions then change back in the summer (Thinking France, Switzerland etc) so he said ‘you must be able to alter it like for like, I’ll just have to find it’. Hey presto, 5 minutes later he’s got it.

Will post with update in due course.

Cheers.

That would be a great help as I was thinking of investing in a VCDS cable and software to do this myself, but if it isn't able to make this change then maybe not.

"I’m sure he’d do it for very little"... don't sell him short! , I'd bung him a cheese sandwich or something ...unfortunately your tech guy is not that near to me

What is your situation (if you don't mind me asking) that made you go down this route? I noticed you were talking about 17" Navis, were you also going down the "bigger tyre" circumference path too on your T6.1? Have you noticed any issues since doing this update, bizarre mileage anomalies, weird MPG values, upset navigation issues, problems with adaptive cruise control etc. etc.?

 

[Paul Sussex]

Another consideration with 20 inch wheels is where to keep the spare as I don’t think it will fit underneath.

 

[Swamperise]

Another consideration with 20 inch wheels is where to keep the spare as I don’t think it will fit underneath.

...you might have to opt for the goo in a can option. All the statistics say that punctures are quite rare so less of a need to carry a full 20" spare. Unfortunately one doesn't give two hoots about statistics when you're stuck by the roadside with a flat tyre! You could just have an emergency underslung OEM one as long as the specs (in terms of rolling radius) matched the 20" ones until you could get the 20" one repaired/replaced.

As I was going for the "swamper" look I was looking at options to rear mount the spare to further the "over the top/unnecessary" styling of the swamper aesthetic!

 

[Vinyl1210]

Ok. Questions, questions.

What is your situation (if you don't mind me asking) that made you go down this route? I noticed you were talking about 17" Navis, were you also going down the "bigger tyre" circumference path too on your T6.1? Have you noticed any issues since doing this update, bizarre mileage anomalies, weird MPG values, upset navigation issues, problems with adaptive cruise control etc. etc.?

I specced mine with standard 16’s (Alloys) when I ordered as I always wanted aftermarket wheels. For me , my van spends a lot of time on less than ideal (rough surface) muddy side roads, country lanes and bumped up verges so I wanted something appropriate. I’ve always liked the Swamper look, hence the choice. I didn’t want 19, or 20 inch wheels. They just wouldn’t suit my vans use. Not saying I ‘off road’ or anything, as it’s a 2WD and I never wanted 4WD, but for me the set up is a ‘robust choice’. Urban Swamper if you will.

Edit to say see this thread for pics.

What Have You Done To Your Van Today?

Fitted a towbar from PF Jones. Really nice and neat design and no bumper cut is needed. (Each tailgate light is white or red, depending on how quickly I flick the switch on and off and on again - if that makes sense!)

www.t6forum.com

Re: issue with other systems (mines on standard suspension at the mo - but will lower maybe 10 mm or so later) no issues at all. I’ve got ACC, high beam assist and all good. Don’t use nav as I have Apple CarPlay.

MPG is good (I’ve calculated against OB computer).

Bit off topic but as you asked:

If you’re an ‘idiot’ on wet roundabouts it will understeer like a pig on the AT tyres, but it’s a van!! So handling wise no worries. Nice and comfy. No excessive roll other than what you’d get anyway and lowering slightly with updated springs in future will help.

That’s just my views.

Another consideration with 20 inch wheels is where to keep the spare as I don’t think it will fit underneath

Yeah. TBF didn’t really think about that before I changed. DOH!! However, I’m fitting a full length overland style roof rack (for solar panel, safari style awning etc) so I’m going to lob a suitable steely up there to cover any (hopefully never) puncture. I have a tailgate and don’t like the look of a spare on the back (or like the idea of added weight on the tailgate). I’m always jumping in and out and raising it so for me a faff. But you are correct. Should be a consideration as the standard steely will just let you get four wheels on ground whilst you get puncture sorted.