Wheel Rims

[Steve24]

I've recently purchased an Audi A7 3.0 TDI BiTurbo and one of the first jobs was to replace the two front tyres, but I was gobsmacked at the price of them (£230 each fitted) because they are 21" tyres and the rims are by far the biggest I've seen fitted to a car.

The guy who fitted the tyres said that for most tyre depots a 21" tyre would be a special order and quite expensive and asked if I was keeping the car, if so then I may find it beneficial to fit smaller rims.

My Audi A5 3.0 TDI has 18" rims, but if was to change the rims on my A7, what would be the best size to fit.

[Magnet]

Hello Steve,

I think you have just found the downside of increasing wheel diameters - as many do to make it look smarter. 
Decreasing from 21 inch to 18in is a big jump, and will result in a very much increased tyre profile. 
I used to get my calculator out and work it out for folks on here, but fight shy of doing that now.

There are websites which do the maths for you - worth searching these out.

Kind regards,

Gareth. 

[Steve24]

Hi Gareth

I purchased the car with the 21" wheels without realising the cost of the tyres, I was thinking of putting on 19" or 20" wheels

Regards

Steve

[Magnet]

Thanks Steve, 

What does your Owners Handbook list as wheel option sizes? There will be tyre widths and profiles listed for each of those options, to ensure the total radius of wheel and tyre profile remains the same for varying dia. wheels. 
Kind regards,

Gareth. 

[Steve24]

Hi Gareth

There are several options available for my car although strangely enough the 21" wheels are not listed, but the options available are 17", 18", 19" & 20", so it looks like I can fit pretty much what size I want from 17" and I'm favouring 255x40x19 and a quick looks shows that the cost of the tyres is cheaper than the 21" tyres I've just purchased.

Having looked for spare rims for my car, the rim currently fitted is £900, so that's around £1100 per wheel with a new tyre fitted, so I could easily sell all 4 for over £3k, which should be more than enough to buy new rims and tyres.

[Magnet]

Thanks Steve,

I’m not surprised 21 inch wheels were not an available option. As has been said, the the bigger the wheel dia. the lower the tyre profile needs to be, and that results in a compromised ride quality. 
You obviously have a wide choice, but can I ask if you’re chosen 225/40/ is the Audi stated tyre size for the 19 inch rims? 
‘…easily sell 4 x 21 inch wheels and tyres for over £3K….’. 
Um! 
Kind regards,

Gareth. 

[Steve24]

Hi Gareth

Just checked and the standard size tyre that Audi recommend for a 19x8.5 wheel is actually 255x40, these have an offset of 32.

I've read that there are a several benefits to putting on smaller wheels like a better ride, better fuel economy, quicker car, cheaper tyres, it makes you wonder why they fitted those huge 21" wheels.

With each of the 21" rims costing £900 and given they are all in VGC and with a legal tyre on them I would have thought I could sell them for £3k, what do you think they would be worth.

Regards

Steve

 

Edited December 20, 2023 by Steve24
More text

[Magnet]

Thanks Steve,

Great - so the tyre  size you will need is 255/40/19, and you will now be able to work out the cost benefits of buying those tyres rather than 21 inch. 

Re. the anticipated selling price for your 21 inch rims with road-legal tyres - apologies Steve you could be right in your belief that you can easily sell £900-new rims as secondhand with road legal tyres for £750. Sorry, I’m not sufficiently experienced to judge, so please ignore my earlier comment.

Kind regards,

Gareth. 

[Guest]

I thought I'd post here instead of opening a new thread as I have a similar question. I'm thinking about getting a set of 17" A6 alloys for fairly cheap, for winter/ride quality. The issue I can see is that I would be going from 265/255 (can't remember) width to 225 width. I can imagine grip would be reduced, but could anybody see an issue with this?

[Steve24]

I'm not sure what size of wheel you currently have, but Audi have told me that I can definitely come down from my 21" wheels to 19", which is what I wanted.