EH52WRX

iTrader: (16)

I have just sold my ford st tdi and i have bought an Audi Allroad 2.5 tdi. I really need an estate. My question is, as they have horrible alloys as standard. Can you fit staggered alloys to them. Something like 20x10 rear, and 20x8.5 on the front. I am not asking if they will fit, i am asking if you can fit staggered wheels to a 4x4. Thx guys

Midlife......

iTrader: (2)

Surely that would simply wind-up the centre diff ??

Shaun

EH52WRX

iTrader: (16)

Hi Shaun,

please explain, as i am not the most mechanically minded.

Midlife......

iTrader: (2)

I'm not that mechanically minded either LOL ........but I was under the impression that the front and rear wheels had to be rotating at the same speed, like a 4 wheel drive can't be towed on two wheels. Maybe I'm getting mixed up with a Torsen (Torque sensing) diff.

Now I'm confused

Shaun

TinyTim

iTrader: (3)

I dont think it'll affect it, as you're only increasing surface contact area and not rotating circumference.

R1CH D

iTrader: (8)

you need to match the profiles to stop winding the diff.

BOB.T

Different widths should be ok, as long as the overall diameter is the same. But don't come to me for new diffs

Midlife......

iTrader: (2)

ooops.....didn't read the OP correctly. Hopefully thay should be the same diameter

Shaun

mervil

iTrader: (5)

I thought as long as the diameters are the same ie 20s then they should be fine!

gallois

it is fine PROVIDED that you accurately calculate the rolling circumference and match them, and this is almost impossible to do.

i.e. a 225/40/18 has a smaller circumference than a 235/40/18.

have a go here http://www.alloywheels.com/tyrecalc.asp

tony de wonderful

You could run the same tyre if you stretch it over the rear.

EH52WRX

iTrader: (16)

I was told to put 35 profile on the front and 30 on the rear.

gallois

225/40/20 are within 1.5mm diameter of 255/35/20, that is ok. (the equivalent of .75mm difference in tyre wear.

EH52WRX

iTrader: (16)

I new use guys would know your stuff. LOL

TinyTim

iTrader: (3)

Which is all well and good, but has no bearing on rolling circumference, so doesnt matter here.

gallois

of course it does

gallois

225/40/20 = 688mm
235/35/20 = 686.5mm

1.5mm difference

TinyTim

iTrader: (3)

If you use the same size, height and make tyres, the width wont affect the rolling circumference, thus all wheels will be rotating at equal rate.

EH52WRX

iTrader: (16)

So why can you fit them to a subaru.

TinyTim

iTrader: (3)

Says who? I see no reason why staggered wheels would affect any AWD/4WD system - it doesnt stop them rotating at different speeds which is the important factor.

gallois

profile is actually a percentage of the width of the tyre. a 225/40/18 tyre is an 18inch INTERNAL size (i.e. fits an 18" rim) that has a width of 225mm, the profile of 40 is actually 40% of the width i.e. the sidewall is 90mm from the edge of the rim to the edge of the tread.

so 225/40/18 = 18" PLUS 90mm plus 90mm
and 255/35/18 = 18" PLUS 89.25mm plus 89.25mm

tony de wonderful

It will upset the grip balance between front and rear for a start.

gallois

I don't think you'd notice on an old audi, it would go from numb to interestingly numb.

Luminous

iTrader: (3)

No, I am afraid that is not the case. As stated a few posts below yours given the wheels he plans to fit are different widths, then the tyres will also be different widths. Having different widths, but using the same aspect ratio will bugger things up

I have no idea on an Audi how close you need the overall rolling circumference to be. I have heard rumours on VX forums that for the 4x4 Calibra and Cavalier people had to rotate tyres back to front to ensure equal wear over the life of their tyres to preserve the centre diff. Those who did not ended up knackering the centre diff.

I think you are going to have to ask on an Audi forum about just how robust your centre diff is. If there are issues with them failing, then I would not do what you are planning.

The Zohan

To be pedantic you need to match the 'rolling radius', not necessarily the profiles

Midlife......

iTrader: (2)

The radius does not roll as it's well.......a radial. It's the circumference which traces the contact with the ground

Shaun

EH52WRX

iTrader: (16)

This is the look i am going for.

http://www.cardomain.com/ride/3210860/2001-audi-allroad

EH52WRX

iTrader: (16)

So did we come to a conclusion guys.

f1_fan

iTrader: (9)

Yes keep the rolling circumference the same or as near as damn it and you will be fine.

EH52WRX

iTrader: (16)

so 245x35x20 all round or 255x30x20 rear and 225x40x20 front