Changing wheel size with dynamic chassis control

[mcmaddy]

Speedos are allowed a % to over read so the difference between 18s and 19s will fall between that %.

[Exonian]

This thread was over and done with at jv’s post.
Nail on head.





It doesn’t surprise me the VW dealership recommended not to change wheels, there can be many aspects to that ranging from ignorance to duty of care in case an owner rushes out to bolt on a set of pig iron lumpen things that cause undue stress on the suspension. A dealer will always recommend (officially) to leave everything well alone.


One thing I’m curious about with the OBD adaptations is whether they might adjust the steering to take into account wider wheels and tyres.

The R is notorious for having a rubbish turning circle when specced with 19’s from the factory.
My ED40 (manual) originally came with 18” wheels and had quite sharp steering and a decent turning circle. My TCR originally specced with 19” wheels definitely seems to have a worse turning circle often needing an extra shunt to get it into a parking space neatly.

[Gnasher]

This thread was over and done with at jv’s post.
Nail on head.





It doesn’t surprise me the VW dealership recommended not to change wheels, there can be many aspects to that ranging from ignorance to duty of care in case an owner rushes out to bolt on a set of pig iron lumpen things that cause undue stress on the suspension. A dealer will always recommend (officially) to leave everything well alone.


One thing I’m curious about with the OBD adaptations is whether they might adjust the steering to take into account wider wheels and tyres.

The R is notorious for having a rubbish turning circle when specced with 19’s from the factory.
My ED40 (manual) originally came with 18” wheels and had quite sharp steering and a decent turning circle. My TCR originally specced with 19” wheels definitely seems to have a worse turning circle often needing an extra shunt to get it into a parking space neatly.

I thought all R's were blessed with a poor turning circle?

I changed from 18s (225/40) to 19s (235/35) and there was no need to change the amount the wheels turned. No rubbing on lock at all - admittedly the different offset may have been a factor in this but there was plenty of clearance around the tyre.

As an aside (and assuming the multiple GPS apps/tomtom are all accurate) it actually made my speedo more accurate (although it was a minimal change).

[Exonian]

I thought all R's were blessed with a poor turning circle?

I have a vague memory of owners complaining the ones with 19’s were even worse than ones specced with 18’s. Possibly a placebo effect(?)
My R definitely had a worse turning circle than the GTI PP I had immediately beforehand, both came originally with 18’s. I swapped to 19” wheels on both cars (all with different offsets but all 8J width) and never had any issues with fouling either.

I can’t directly compare R to TCR as it’s now over three years since i last sat in the driving seat of an R.

[Watts]

My TCR originally specced with 19” wheels definitely seems to have a worse turning circle often needing an extra shunt to get it into a parking space neatly.

I thought this but kept putting it off as being my imagination! When I drive into a parking space I often have to reposition myself which I never did with the PP. Could VW have fitted the TCR with the R steering rack?

[JB GTI]

My Mk7 R with 19” factory wheels had an appalling steering lock. my Mk7.5 GTi PP with 19” factory wheels is night and day better 

[dubber36]

Just a thought, but even tho' rear drive shouldn't be engaged, do they have less steering lock to limit the speed difference between the left and right rear wheels when maneuvering, which would ordinarily cause diff wind up in a permanent 4WD vehicle?

[Exonian]

Even though the Haldex uses clutches to engage and disengage drive (rather than permanently coupled 4WD) the reduced steering lock must still be at least in large part to do with the diff. I’m sure there are a good few R owners on here who must know the official reason(?).
God knows why the TCR seems to have a poorer lock than a regular GTI though.



Anyway back on topic, as said here many times, it’s fine and dandy to change up a size of alloy wheel even with DCC but do try and get a fairly lightweight wheel (or at least a reasonably comparable weight to the wheel coming off) and keep your tyres correctly inflated to reduce any additional wear as much as possible. The car will drive better with lighter wheels and proper air pressures and it won’t wreck ride quality. .