Swapping 19" to 18" or even 17" wheels on a A4 Avant S-line

[white_shark]

Hi all,

I am trying to figure out the best course of action for replacing my rims and tyres from 245/35 ZR19 93Y XL (currently fitted) to 245/40 R18 94H or even 225/50 R17 94H on an A4 avant s-line.

The reasons to do that:

1. The rear tyres are worn out badly, probably due to the lack of wheel alignment
2. I really dislike the bumpy ride and too low profile
3. The differential knocking when wheels are fully turned one way is really bad and is said to be worse on the lowest tyre profile

So according to the wheel size calculator, 19" to 18" should be almost identical. 654mm overall wheel height for 19" vs 653mm for 18". 

But is there anything I am missing here? 

What alloys won't look terrible? I kinda dislike the current look anyways as the profile is too low and the car isn't sporty at all with its laughable 35 tfsi engine. But nonetheless, I'd prefer to keep it look nice.

Thanks for recommendations in advance!

[Magnet]

Hello,

I’m sure you’ve got the logic in the right place with this, and there is one thing for certain- Sports suspension coupled with ‘fancy big wheels’, dictating low profile tyres, with the ‘extra load’ specification, all adds up to an uncomfortable ride. 
I haven’t used the wheel size calculator - preferring my old maths! - but it all boils down to using the smallest diameter wheel that was available on your model at the time - the important bit being that the rolling diameter is maintained, by increasing the profile by the correct amount as the wheel diameter decreases. 
To enhance ride quality, it would be advisable to stay away from XL tyres unless you are carrying heavy loads in this estate car. If at any time you are carrying such loads then obviously you will need XL.

OK, pessimistic, but having increased tyre profile via. smaller wheels, you will still be left with the inherent stiffer suspension of the S Line, but……

Kind regards,

Gareth. 

[white_shark]

Thank you for response Gareth,

Yes I don't expect to miraculously get rid of the 'sport' suspension effects and more to that, I am thinking about replacing my current tyres with run flats. Which should make the situation even worse, or at least cancel out the 19" to 18" swap 😄

 

[Magnet]

Hello Shark,

If you are looking for improved comfort, why on earth are you looking to use run-flats, and put up with their inevitably much firmer sidewalls - unless rim design dictates. 
OK no one can argue about the significant benefits of run-flats on the safety scale, but it’s a bit like walking around and going dancing in safety boots - Incase something falls on your toes! 
Kind regards,

Gareth.