4Motion 18” spare wheel , real facts only.

Vwcaliforniajapan · Jan 18, 2020

I read many posts about 18” spare wheel, but I need real facts from those of you who found the exact size for a 4Motion and how to fit it under the car, please.

WelshGas · Jan 18, 2020

1whitesamurai said:
I read many posts about 18” spare wheel, but I need real facts from those of you who found the exact size for a 4Motion and how to fit it under the car, please.

You don’t need an 18” wheel. It is the overall diameter/circumference of Wheel + Tyre that is important.
You can use a 17” wheel + standard tyre that would give the same diameter/circumference as your 18” wheel + tyre combination. It will fit the Spare Wheel carrier and can be used as a Get U Home spare with no problems.

B J G · Jan 18, 2020

I tried a VW Amorak 7.5Jx18" Durban wheel on my T6 with a 235/55/18 104V tyre and it fitted. A 235/50/18 101V tyre would more of a match for a 255/45/18 if that's what is currently fitted in terms of keeping the gearing correct.

Vwcaliforniajapan · Jan 18, 2020

B J G said:
I tried a VW Amorak 7.5Jx18" Durban wheel on my T6 with a 235/55/18 104V tyre and it fitted. A 235/50/18 101V tyre would more of a match for a 255/45/18 if that's what is currently fitted in terms of keeping the gearing correct.

Thanks, I ordered Springfield 255/45/18
so 235/50/18 101V will be ok for 4Motion ? How will it fit under the car, do I need a different bracket to keep the spare wheel in place ?

B J G · Jan 18, 2020

1whitesamurai said:
Thanks, I ordered Springfield 255/45/18
so 235/50/18 101V will be ok for 4Motion ? How will it fit under the car, do I need a different bracket to keep the spare wheel in place ?

Main point is not go over 7.5" width rim as it may touch both the floor and carrier bracket. The carrier is designed to take a 235 width tyre. I personally haven't tried an 8" wide rim.
VW UK dealers sell 235/50/18 101 on 18" wheel option to van owners. 101 is 825kgs - 1650 per axle. OK as a spare but punctured wheel will probably need to go inside until repaired/replaced.

Vwcaliforniajapan · Jan 19, 2020

B J G said:
Main point is not go over 7.5" width rim as it may touch both the floor and carrier bracket. The carrier is designed to take a 235 width tyre. I personally haven't tried an 8" wide rim.
VW UK dealers sell 235/50/18 101 on 18" wheel option to van owners. 101 is 825kgs - 1650 per axle. OK as a spare but punctured wheel will probably need to go inside until repaired/replaced.

thanks, to keep the punctured wheel inside is the smallest problem as long as I can move on.
‘Do you actually know some who used the 235/50/18 101V as a spare wheel on a 4Motion ? I mean it sounds like you know what you are talking about but I just have to make sure that I don’t F...up the 4motion ha ha I’m sure thats not an say fix......and nobody have spare parts here in Japan.

B J G · Jan 19, 2020

1whitesamurai said:
thanks, to keep the punctured wheel inside is the smallest problem as long as I can move on.
‘Do you actually know some who used the 235/50/18 101V as a spare wheel on a 4Motion ? I mean it sounds like you know what you are talking about but I just have to make sure that I don’t F...up the 4motion ha ha I’m sure thats not an say fix......and nobody have spare parts here in Japan.

The rolling radius is virtually identical, which is the critical thing with 4M in keeping wheel rotations synchronised. not as critical as first 4M or Quattro was when it was advised to have to have all tyres with matching tread depth.
It gets more complicated if you had eg a 255 with 4mm tread left and a new 235 with 8mm new tread to compare.

Overall a 235/50/18 is as close a match as you can get in 18". A 17" 235/55 tyre isn't a 100% match, see calculator below for actual percentages.

Tyre Size Calculator

A better easy to use tyre size calculator. Use our tyre size calculator to find tyre diameter, width, sidewall, circumference, and revolutions per mile.

tiresize.com

Vwcaliforniajapan · Jan 19, 2020

B J G said:
The rolling radius is virtually identical, which is the critical thing with 4M in keeping wheel rotations synchronised. not as critical as first 4M or Quattro was when it was advised to have to have all tyres with matching tread depth.
It gets more complicated if you had eg a 255 with 4mm tread left and a new 235 with 8mm new tread to compare.

Overall a 235/50/18 is as close a match as you can get in 18". A 17" 235/55 tyre isn't a 1005 match, see calculator below for actual percentages.

Tyre Size Calculator

A better easy to use tyre size calculator. Use our tyre size calculator to find tyre diameter, width, sidewall, circumference, and revolutions per mile.

tiresize.com

Thank you very much for all your help.