Biggest wheel size

[Tim21]

Hello everyone 

I need some advise

just purchased an A5 it came with 17” wheels

wanted to change them to 20”

255/35/20 or 275/35/20

being advised I can go up to 21”

275/30/21 expensive 🧐

but also found some fantastic deals on 22”

275/35/22

What’s your poison and advice

just trying to pimp it up 🤪

 

 

 

[Magnet]

Hello Tim,

Thanks for the question.

You don’t tell us the width and profile of the tyres on the current 17 inch wheels - hope these are the original size wheels since that is important.

It’s not going to be possible to comment on your proposals until you give us this information since the theory is that whatever the outside diameter of the original wheels plus tyres are, that rolling diameter must be maintained when fitting larger wheels - so the more wheel, the less tyre height (profile) you are going to get away with. 

While we await that information, it worth bearing in mind that (sorry, but probably the bleeding obvious) lower profile tyres will result in the ride quality approaching that of fitting solid tyres! Other points :- OK, it may be looked upon as ‘looking smart’ with larger wheels, but in reality, it means nothing to the driver since he cannot see the wheels when he is driving the car! - so the beauty is simply in the hands of some other ‘passer by’ person. Couple that with the need to inform your insurer that you have non standard wheels fitted to the car, and it may all become a bit of - why bother? 

Anyway Tim. Current tyre sizes, and known to be a standard fitment on your model? 

Kind regards,

Gareth. 

 

[Rudis_Dad]

Whatever size you put on, you need to have an equivalent outside diameter to your current fitment +/- 5mm. If you don't fit a similar equivalent size you will affect the speedo reading (smaller wheels will cause the speedo to over-read, larger will cause it to under-read); in addition to this it can also affect gearing if the difference from your fitted size is too extreme.

For comparison, 255/35R20 has a nominal O/D of 686mm; 275/35R20 is 701mm (+15mm over the 20" wheels) and 275/35R22 is a whopping 752mm (+66mm!!) - but as Magnet has said, unless you can tell us the size of tyres currently fitted, it's difficult to give an properly constructive advice.

My A5 has 20" wheels fitted with 255/35R20 tyres; as a result the ride is unforgiving, and the grip level in cold/greasy conditions is suspect (the car understeers appallingly if pushed too hard into corners and the road is anything less than bone dry - Quattro or no Quattro...)

Too big wheels/tyres can also cause issues with rubbing/knocking on full lock.

Personally, I wouldn't go bigger than 20"; they fill the arches nicely and are probably the best compromise when it comes to aesthetics and performance. I know that I'll be getting a set of 18" wheels with appropriate tyres for next winter.

Edited March 16, 2020 by Rudis_Dad

[Magnet]

Hello John,

It’s refreshing that you have taken time and shared your knowledge, and more importantly meaningful experience, to try to advise someone who has sought advice on this forum. 

What a shame that the original poster has not returned to the forum since the day and time he first registered. 

From a personal point of view, I seem to spend quite a bit of time and effort in trying to help on here, but I am rapidly getting to a point where I am beginning to think twice about bothering, since it does take a fair amount of time and interest to share experiences, and there now seems to be an increasing number of post-and-run folks signing up, or return visits or requests for further information.

Very little feedback, even less acknowledgement, and the word ‘thanks’ seems to a word which must be difficult to spell! 

That’s my rant for the day, and possibly a biased opinion, but....

Ta, ta, to this lot??! 

Anyway John, we must live in hope that your valid experience may be of help to someone else in the future. 

Kind regards,

Gareth. 

[Rudis_Dad]

I know what you mean Gareth, it does seem that there's very little meaningful interaction on this forum - it's much the same on the A5 Owner's Club forum. There seem to be a lot of people viewing posts but very few actually contributing to the forum.

I think that the issue is that there are fewer petrol/diesel heads about, and many more people who have a passing interest in cars - I suspect that the latter are in the greater majority here. I also think the fact that an Audi is now much more a lifestyle statement than ever before ("Look at me, I've got an Audi!! I don't know or much care what makes it tick, but I've got one!!!) and you've got a recipe for little if any interaction.

Shame - the VW scene is much more vibrant. Luckily I have both so I can get my fix one way or the other!!

[esky365]

Speaking as an occasional poster. I appreciate all the advice I get.

As soon as I buy a car, I join the appropriate forum.

My mechanic does most of my work, but he is old school, so I often go in to collect the car, and he will tell me what he has done, and what he didn't have time for. Basically, if it is fitted with a nut and bolt, he is THE MAN, other than that, it depends. 

But, yes, please don't stop posting you petrol/diesel heads are great. THANKS 🙂

[danut]

How you put the 255 / 35 R20?  they are not in the audi book?

[jdragon]

The only comment I can add is posted here 🙂

https://www.audiownersclub.com/forums/topic/25171-audi-a5-b9-tyres-25535-r19/

[Hammie1982]

A quick google search or Wheel Fitment search on the internet will give you alot of information.

Most of it, isnt worth your time reading.  But over my 42 years and 36 of them being around cars.

I have found that there is plenty of information out there that will help. But you need to know where to look.

 

As far as i am told by a tyre fitter here in town, "you can get 22" wheels on an A5, but it depends on the suspension setup and the width of the wheels". "Your very likely to get rubbing issues and overstress the wheel bearings and bushes on the car but it can be done" "It depends on the Engine, the model and the year"

Ill refrain from asking the follow up questions that he put to me in regards to 22" wheels on a "Smaller car".

Bare in mind, I drive an A8 and he nearly chewed my face off when i asked him for a price for tyres for 21" wheels......
He went on to say about pickups having wheels that size etc.
(Hes a good bloke, ya just have to know how to handle the grumpy sod)

Being honest and having had all different types of wheels on all different types of cars over the years, I wouldnt be advising going any bigger than 255/30R20 on the car if you want any kind of longevity out of the wheels or  your spine.  The roads are not freshly laid nor are the potholes forgiving to any wheel on less than a 25/30 profile tyre
(Thats just my opinion)