Wheels

[Embalmer1andy]

Hi everyone.

I have a Audi A8, 4.2tdi currently running on 275/30/21 tyres and i am having a lot of damage to wheels and tyres due to all the pot holes.

will a 275/40/21 tyre fit on my car.

Any help would be appreciated.

Andy

[Crasher]

I am on 18’s with 225/40’ and have buggered two expensive alloys lately, I replaced one after I hit an engineering brick on a dark wet road (just past a Jewson depot...) and buckled it within two weeks on the same road opposite the same Jewson depot but a pothole this time.

Going to a 40% profile is a circa 7.7% increase in diameter which will make your speedo under read by nearly 3.5%, the best solution is to lose the look of 21’s and go to 19’s with a 275/50 tyre.

[Embalmer1andy]

Thanks for your reply.

i have kept the 19" wheels that came with the car and they are 245/45/19 but they seem lost on the car,plus they don`t look that good. The 21" rotors look good but they are not realistic especially with all the pot holes.you feel every bump. i have put 2 tyres in on 3 weeks at the cost of £275 each. Would a 20" rotor with 275/45 be ok.

Andy

[VAG-Abound]

Looking at specs for models a few years old, are you sure the ones on 19" wheels aren't 255/45? 275/40 on the same rims gives similar overall diameter, if I'm working it out right on my phone's calculator...

And 275/35 seems to be standard on the 21", so that would get you part way to /40, and correct what may be an overread on speed / distance.

[ArcticHammer]

If you have a D3 you could try 275/35-21. Should increase rolling circumference with 4%(5,2% increase from standard, and 5% is max allowed). And radius with 1,4 cm. 275/40-21(increases rolling circumference with 8% and radius with 2,75cm) will be too big and most likely touch something.
A friend has been driving with 265/40-20 on a D3 without problems.
If you have a D4, 275/35-21 is recommended and 275/40-21 could fit. It will be just over a 5% increase in rolling circumference from standard.

[Crasher]

Andy, could you private message me your REG number so I can check what is possible.

[JohnF]

It's a bit of a late reply, but it might help some. My D3 W12 sport quattro with 255/40/19 needed new tyres. They are quite expensive, but I found some on-line 255/45/19 for less than £60 each, plus a tenner for fitting at a local tyre place. If my maths is correct, they have increased the diameter by 3.7%. Not only have I got more tyre for far less money, there is also more protection from potholes, and in theory a slightly quieter and more comfortable ride. They also suit me better as the car is lower geared compared to its A8L limo cousin for better acceleration, giving only 30mph per 1000 revs in 6th. I would have liked it to be more 'long-legged' which it now is, although I can't say I've noticed much difference. Just have to allow for speedo error now!