Wheels/Tyres: Traction

[Pieter11]

I have a one year Active. Front tyres are down to 2mm on left hand side and 5 mm on right so about to change both of them.

Recently when on full lock turning right you can feel the right tyre 'slipping' - feels like a series short skids - and wonder if this the traction control system operating (either correctly or incorrectly)?

Also any views on why the wear between left and right tyres is so great - something to do with the wheel alignment not being correct?

Thanks

Pieter11

[ex Triumph Man]

Sounds odd that does. I presume your tyre pressures are equal and tracking etc OK?
Incidentally what is the mileage recorded?

[PsYcHe]

Get the tracking checked out.. Though have you maybe been a bit heavy on roundabouts? That can cause excessive wear on the outside tyre.

[bobdabuilda]

Originally Posted by Pieter11

I have a one year Active. Front tyres are down to 2mm on left hand side and 5 mm on right so about to change both of them.

Recently when on full lock turning right you can feel the right tyre 'slipping' - feels like a series short skids - and wonder if this the traction control system operating (either correctly or incorrectly)?

Also any views on why the wear between left and right tyres is so great - something to do with the wheel alignment not being correct?

Thanks

Pieter11

That's how mine is and even with new tyres on it doesn't make a difference. The previous set wore the outer shoulders of both fronts whilst the inner 2/3 of tyres had 5mm still! Had tracking and balancing but still no difference. Dealers said nothing wrong so I have now assumed it's just a feature of the car! let me know if you find the cure!

[kentishdriver]

Originally Posted by bobdabuilda

That's how mine is and even with new tyres on it doesn't make a difference. The previous set wore the outer shoulders of both fronts whilst the inner 2/3 of tyres had 5mm still! Had tracking and balancing but still no difference. Dealers said nothing wrong so I have now assumed it's just a feature of the car! let me know if you find the cure!

Mine as well. Had perfectly legal tyres except the outside edge of the OSR, which I had switched from the NSF at about 9000 miles to eke out a few more miles. At 9000 the NSF was down to less than 3mm. By switching managed to get another 9000 miles out of it.

[DCO]

The tracking is crucial and from some peoples experiences as reported elsewhere on the forum, are not always adjusted correctly by some dealers / tyre places, so it may be worth getting it re-checked.

If you are using the standard tyre pressures it is worth raising them. I found that adding 4psi-5psi made a big difference in the wear rate of the shoulders, as well as improving economy slightly. If you regularly run the vehicle with a fair load on board then raise the pressure up to the 39psi "eco" settings. I do not use the full "eco" pressure as I have found that with the load I normally have on board, 39psi makes the centre section of the tyres wear more than the outer sections.

[Clan]

Originally Posted by bobdabuilda

That's how mine is and even with new tyres on it doesn't make a difference. The previous set wore the outer shoulders of both fronts whilst the inner 2/3 of tyres had 5mm still! Had tracking and balancing but still no difference. Dealers said nothing wrong so I have now assumed it's just a feature of the car! let me know if you find the cure!

Yes it is a feature of the car when run with low tyre pressure , try 36 rear and 38 psi front it will transform the car and make a big difference to the edge wear ..

[bobdabuilda]

Mine are 38psi all round Clan but I will try lowering the rears to 36 and report back.

[RFW]

Next time you have the chance to park somewhere flat leave the car on full lock and then stand in front and observe the really odd geometry angles; the outside edge of the 'outside' tyre will be tucked under. Then imagine that view with the moving weight of the car and it's no great surprise that the outer edges tend to wear away (even with moderate driving habits). Exiting my drive onto the road is a downhill/full lock exercise and my XC90 has always exhibited "scuffing noises" as the tyres go sideways.

As Clan says, keeping the tyre pressures high will minimise the edge wear.

A good general purpose tip (applicable to any vehicle) to judge between 'problematic' and 'normal' edge wear is to measure the tread depth of the three or four main grooves and if they are within a couple of mill' across that flat section then there isn't much wrong with the geometry settings. For example my 2010my 3.2 XC90 showed half a mill' difference between the four grooves (factory fitted Continental Cross Contact UHP 18") when I changed them at twelve months/19780 miles although a glance at the wear on the outer shoulders would have suggested the tracking was incorrect.

[Clan]

Originally Posted by bobdabuilda

Mine are 38psi all round Clan but I will try lowering the rears to 36 and report back.

The rear tyres tend to wear on the outer edge which may be too much toe in sometimes , but most of the cases i have seen , the rear pressues have been running less than 30 psi for some period of time .. Luckily the XC90 doesnt seem to suffer ride issues with various pressures so experiment to see what suits you best .