Tyre outer edge wear

[Patrick Bateman]

Can anyone decipher this tyre wear? I’m not sure if it’s a simple alignment issue or driving like a tit potentially? XKR had its MOT today where one front tyre had an advisory for wear on the outer edge.

The car fairly recently had an alignment after getting both track rod ends replaced, however, other than the toe being correct the other readings were still out of tolerance. In hindsight I should have challenged them on an explanation but I suspect it’s of limited impact here as these tyres must be on around almost 20k miles now.

Offside front with advisory for outer edge-





Near side front no advisories-


There’s still a reasonable amount of tread left on them and I’m not sure how clear it is to you but as per the second photo, the main section of tread that’s closest to the outside of the tyre is actually the deepest. If the camber was way off I’d expect that to also be more worn than the inside but that’s not the case.

[GreenV8S]

Hard to get a clear understanding of the state of the tyres from a couple of pictures, but that tyre with the advisories looks worn on both edges, which might be a sign of being run under pressure. Wear on the outer edges of both front wheels might also be a sign of too much toe-in. Even if the settings look fine on the ramp, you may find something is deflecting under load - for example those track rods you had replaced.

[Patrick Bateman]

Totally slipped my mind but now you mention under inflation…I keep these topped up every 2 weeks or so as I didn’t use to realise they slowly lost pressure down from the recommended 30psi to about 25psi in a month-ish. Not sure if this was always the case since fitting but I have been running them at about 33psi for a bit now as the steering could be excessively heavy when trying to park given their size and low profile.

That being said, the outer edge is definitely worse. Here’s a better one to show both edges-



In terms of replacing, is it fine to run these for a bit yet (whilst keeping an eye on the outer edge of course) given the central 75% of tread depth is comfortably above minimum? I was hoping I’d see the summer out with these.

[E-bmw]

Well over 75% of the tyre width is well over 1.6mm, they are fine for a good while.

The idea of an advisory on an MOT is that they are unlikely to pass next year, so they are warning you to keep an eye on the advisory point.

[Haltamer]

Perhaps this is a bit of a Jaguar feature..

I've got a similar pattern of wear on my XF - It's as though it's been run under inflated - but they're not (Checked manually regularly, when temps change, TPMS)

The alignment is all in spec..

I do note that the OEM Tyre specification (245/45) is on a quite narrow (OEM) Wheel - 8J, where most guidance / experience points to a minimum of 8.5J for a 245 section tyre - That being said, I'm sure the JLR Engineering team have some reason for this!

I wonder if it may be a combination of vehicle weight and some quirk of dynamic geometry inherent to JLR Suspension designs?

That all being said, the overall tyre life is still quite acceptable - I'm nearing 40K with the current set of Vredestein Quatrac Pro's on the front, with ~4mm across the centre of the tyre but some visible extra wear starting to show on the edges - So nothing I'm going to invest effort into 'fixing'!

ETA: To chime in on the opinion piece, I'd probably be looking to replace those - Even if they're theoretically in spec, I start to get touchy by the time there's visiblly 'not much tread at all' on any part of the tyre - On the logic that If it's already wearing quickly, I'll get to the cords sooner rather than later, and there's no indication of when that's going to be until it happens.

Edited by Haltamer on Tuesday 1st July 09:25

[GreenV8S]

The rim width can affect how the contact patch moves under side loads. When you stretch a wide tyre onto a narrow rim, it tends to lift the inner edge under cornering and apply more weight you the outer edge. This exagerates the effects of body roll, which is trying to do the same thing.

If you stretch a narrow tyre onto a wide rim you get the opposite effect so these two components tend to cancel each other out, leading to more even contact pressure distribution.