Changing wheels and tyres please advise

Ken76

Ken76

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Hi I currently have 20” rims with 245/35r20 tyres
I was going to change to 19” rims 8.5j 8j with yr falken 435s tyres being 245/35r19 my question is that because of the reduction of rim size should I go with a tyre with more of a side wall and if so what would you guys recommend? I don’t want too big a gap around the wheel arch. The falken tyres are the same profile as the ones I have on, only different diameter.
Thanks for any advice!!
 
I think if you go for 19" 8.5J et40 wheels with 245/35 R19 93Y tyres that will be a standard fitment for the A4 saloon. That's what I have on mine and its stock. This will increase arch gap a bit but bring it to standard for sports suspension, and speedo will be correct now.
 
jds_sg said:
I think if you go for 19" 8.5J et40 wheels with 245/35 R19 93Y tyres that will be a standard fitment for the A4 saloon. That's what I have on mine and its stock. This will increase arch gap a bit but bring it to standard for sports suspension, and speedo will be correct now.
Click to expand...

Is it possible to get tyres with a higher side wall?
 
Last edited:
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Your standard size for a 2.0 TDi is 225/50 x 17Y; Michelin Primacy are excellent in the wet and v.quiet (68db).
 
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I suppose you could fit 40 profile instead of 35, the diameter would be 24.5mm bigger which would give a speedo error.
Not heard of anyone doing that tbh.
 
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jds_sg said:
I suppose you could fit 40 profile instead of 35, the diameter would be 24.5mm bigger which would give a speedo error.
Not heard of anyone doing that tbh.
Click to expand...
Ok that makes sense then thanks for replying and for your help.
 
I have 35 on the front and 40 on the rear ... i wanted a stock stance . Did not make any difference to my calibration in terms of mph . Tested on speedo Garmin satnav and the wifes gps using her mobile . All read the same .... at town & motorway speeds .
 
k.lockU2 said:
I have 35 on the front and 40 on the rear ... i wanted a stock stance . Did not make any difference to my calibration in terms of mph . Tested on speedo Garmin satnav and the wifes gps using her mobile . All read the same .... at town & motorway speeds .
Click to expand...

I assume no speedo error because the diameter of the front wheels is stock? It wouldn't be that much anyway.
 
Stock alloys on v6 sport are 17"
I have 18" RS6 5 spoke twins fitted .
And my speedo matches all devices
 
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@k.lockU2 and anybody else who knows - what’s the deal with winding up diffs in Quattro cars ? I’m not even sure if k.locks car is a Quattro but my basic understanding of diffs on all- wheel drives is that running different Tyre profiles can be problematic.
What’s the deal people ?
 
Ken76 said:
What size of tyres have you got on the 18s?
Click to expand...
I have 225 40 18 on front & rears are 235 40 18 ... they were 225 35 18 all round the lower profile was wrecking my alloys with kerb damage reverse parking ... narrow Busy-ish street. Many neighbour's have had wing mirrors damaged ... and some recieving scrapes to the side ... hence why I try to park close as possible ... higher walls has helped to keep refurbed wheels stay that way ...
 
Oh - klocku2 - I thought you said ....”I have 35 on the front and 40 on the rear “ that’s why I posed the question about diffs being wound up.
It seem that if your car is a Quattro which has a Torsen type central diff. then you may find that different profiles or even extreme ends of wear spectrum on different wheels can cause problems. I’m not entirely sure what the allowed tolerance is with Audi but with Subaru the allowed difference in wheel circumference was quite small !
I haven’t looked to see what difference in rolling radius is between 225 and 235 but there will be some, So my advice is to just be careful if your car is torsen central diff equipped
 
I thought it was 35 & 40 ... but then i double checked, & tried to recall a lengthy discussion with my tyre supplier 6 months ago . The rear wall is slightly higher being wider. The 40 x 335 x 18 was calculated as I believe to be 1.8% larger overall as the cross section is times the profile . Hence why I though they were 35 & 40.
 
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Ken76 said:
Hi I currently have 20” rims with 245/35r20 tyres
I was going to change to 19” rims 8.5j 8j with yr falken 435s tyres being 245/35r19 my question is that because of the reduction of rim size should I go with a tyre with more of a side wall and if so what would you guys recommend? I don’t want too big a gap around the wheel arch. The falken tyres are the same profile as the ones I have on, only different diameter.
Thanks for any advice!!
Click to expand...
Ken 76 I swear by Falken ... 35 & 40 profile make a huge difference 35 they are so easily scuffed by kerbing even the slightest of graze. Will damage your alloy and not scuff your tyre.
 
k.lockU2, is yours a B9? Looks like the standard tyre on an 18" in 225 would have been 45 profile so even more sidewall to absorb the potholes and kerbs.
 
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k.lockU2 said:
Ken 76 I swear by Falken ... 35 & 40 profile make a huge difference 35 they are so easily scuffed by kerbing even the slightest of graze. Will damage your alloy and not scuff your tyre.
Click to expand...

So 40 on 19s? Can that be done ok?
 
Just to clarify what the standard size wheels and tyres are on an A4 B9 here is an excerpt from the 2018 brochure:

A4 b9 wheels and tyres

You can see that the standard tyre size for 18" is 245 x 40 and 19" is 245 x 35.
I've heard of people going for 255 wide tyres but not higher profile than the standard.
 
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jds_sg said:
Just to clarify what the standard size wheels and tyres are on an A4 B9 here is an excerpt from the 2018 brochure:

View attachment 204075

You can see that the standard tyre size for 18" is 245 x 40 and 19" is 245 x 35.
I've heard of people going for 255 wide tyres but not higher profile than the standard.
Click to expand...
Great thanks that answers everthing!
 
I have 255 35 R20 on mine and it’s fine.

My winter tyres are 235 40 R19, also fine.

Use https://www.willtheyfit.com

It will show you the difference between the sizes.


Sent from my iPhone using Tapatalk
 
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