will 155R13 tyres fit a standard S3?

[reb53]

Good Evening,

Could someone please do me a big favour and post a picture of the spring perches "modified" for 155 tyres. The struts are off my S3 at the moment, so now is the ideal time to modify them.

Thanks in advance.

David

Actually David I suspect the right time to do them is when they're on the car.
That way they're held at their correct angle, they're supported, and as the springs are in place you won't bash them in too far as the bottom coil of the spring is there to stop you.
People assume you're going to have to whack away with a sledgehammer but , certainly in my case, they bent very easily and controllably.

[UAB807F]

I would second the above post, if you do them off the car you'll need to have the spring handy to make sure it will still fit afterwards. The metal is fairly thin (1.6mm ?) mild steel and will move very easily with a small hammer so you're not going to damage anything else.

IIRC mine cleared the 155 tyres which were on the car when I bought it and it was much later when I looked at how close it was that I decided to give the spring seat a couple of taps.

I now have smaller springs with adjustable perches so clearance is no longer an issue but from what I remember I ran the car with probably no more than 4-5mm clearance even after "modification". As long as it's clear all around the circumference I can't see it as a problem. I'd wait and see what you get after assembling it all.

Brian

[Orsom Weels]

On my friends series 3 there was no clearance issues between the tyre & spring perch with 155 tyres, but they just rubbed the wheel arches when the suspension was compressed. I had always thought that was why the arches were flared a bit on the series 4, to allow the use of 155 tyres? I was not aware of any other changes, is there a difference in the relationship of the hub flange & the strut between series 3 & 4?
Regards, Tim

[reb53]

As far as I know there is no difference.
What caught me out was a slightly different sized tyre.
I?d been using 155 tyres for 40 years with no problems so I never suspected them and went chasing all sorts of non existent problems.
I assume there was a slight difference in the shape of the tyre.
Now I?d recommend, ?stick ?em on and see what happens ?.
Probably nothing...

[billwill]

My S3 coupe originally came with 145 tyres. Soon after I fitted 155 tyres and did a little hammering on the rear spring platforms. This worked fine OK, except that the front tyres fouled the arches on full lock.

When I accidentally damaged the front, I had the front including the arches replaced by an S4 nose (it may be that that was the only readily available replacement in about 1972.) Later c 1983 I had a major refurb done and the rear wheel arches were also changed to S4 type.

I ran with 155 tyres for many years until last year when I decided to fit Alloy wheels (thinking that my old steel wheels had done around 200,000 miles and might be subject to cracks). But there was uncertainty about how far out the rim was from the central mounting plate and the alloy wheels are 5" wide not 4.5" , so I decided to revert to 145 tyres.

On the left side all is OK, but on the right-hand side (drivers side in this car) the rear tyre rubs on the inside of the wheel arch by a small amount when the body dips down. I've filed away much of the inner rim of the S4 arch bit I still have a bit of rubbing occurring.

So in conclusion I think the question of rubbing tyres depends on how precise is the centering of the body on the subframe.