Alloy upgrade size


Registered User
Looking to upgrade my 18in on my B9 S-line avant for something different. I’m thinking 19in but wondering if I can squeeze 20in.
Anyone have 20s on their B9?


Well-Known Member
Bronze Supporter
You can fit 20’s on the b9 but it’ll do nothing for your ride quality & turn in will take a hit. If you have the sport suspension 19” fill it out the wheel tub quite nicely. It’s about a inch away from the lip +-


Registered User
If you care about ride quality at all then stick with 18's. On anything other than very smooth roads the ride in mine on 19's is not brilliant - it must be grim on 20's!

If you only want asthesics then go for it, get them on there, it'll look pretty trick.


Registered User
Thanks for the reply guys. I’m so tempted to upgrade to 19s/20s!
But sounds like the 20s are out.
I’ll think on about the 19s!!


Registered User
19s are fine, they've been standard fitment to Sline models for a while now.
My previous Sline had 18s which were also fine, but I don't think there is much difference in ride quality between the two, a little firmer with 19s. But 19s look more suited to the vehicle in my opinion.
They don't fill the wheel arches any more than 18s because the rolling diameter is fundamentally the same, its just there's less tyre and more alloy!


Registered User
I have 19" wheels on my s-line (245/35/19) with adaptive suspension and I would definitely think again before ordering a car with these wheels. On smooth continental roads the ride is great, but on rutted, pot-holed UK roads it is not so good - I have already had one bucked alloy replaced following a pot-hole hit on the M6.

The low sidewall also makes wheels much more vulnerable – I make a number of trips through the channel tunnel and driving on and off the carriages can be tricky with a momentary lapse in concentration resulting in a scuffed wheel.

But that said …. Ride quality is a very subjective thing and I know that many find the ride fine with larger wheels.


Registered User
I went from 19’s to 20’s and noticed no difference in ride quality. Although I did stay with a 35 profile on the 20. I also have 18 winter tyres and hardly notice any difference between them. Tyre pressure makes a massive difference, you don’t need the 40psi the label says. I have 34 at the front and 32 on the rear, always have even tyre wear and the car handles brilliantly. I also still average 48mpg every week travelling 600 miles to work and back, not bad for a 360bhp diesel.
You will always smash down a pothole no mater what size wheel you have. My Mrs golf has 16 wheels with ballon tyres on and it feels no different to mine down the same roads. Granted, the bigger the sidewall the more impact it will take, but if the potholes are that big surely you can see them as you’re driving.
I have adaptive suspension with MSS springs.

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Registered User
but if the potholes are that big surely you can see them as you’re driving.
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In most cases, yes - however in my case it was on a contra-flow section of the M6, at night and heavy rain. BTW - 48 mpg for a 360 bhp diesel is mighty impressive!


Registered User
Most misquoted terminology 'upgrading' going bigger alloys , it's up sizing !

Never an upgrade other than looks as multiple dynamic losses .

To cope with the rebound of increased unsprung mass consider uprating the dampers .


Registered User
I've got 17 inch wheels with 225/50/R17 tyres but I also have the non-sport suspension and I do wish the arch gap was smaller.
The chunky tyre look has grown on me over time but I'm not a fan of the huge arch gap.

I personally think that putting sporty rims that don't fill the arches out nicely looks more out of place than a car with huge ride hight and small stock wheels. With mine, changing wheels doesn't really fix anything for me as I'll still have monster truck arch gap.

I've toyed with picking up a second hand set of the stock 18" S line wheels when I'm due for some new tyres as I'm not that fond of the 17 inch stock wheel design but that still wont do anything for the arch gap.

Of course I could fork out to address the suspension too but it all seems like a lot of money all for the sake of the way it looks whilst likely making the ride worse. Especially whilst in its current form, it's likely one of the most comfortable suspension and rim setups possible on the A4.

Thankfully, when I'm in the car I can't see the wheels or the arch gap but I'd love for it to be different.