Changing tyres question

Morning all,
Recently had my Evoque serviced at a local garage ( totally trusted and known the owner years), was advised that the Front tyre n/s was wearing on inside and to check the geometry. Thought I may as well get a new tyre and have geometry check at same time, however the fitter at shop said that” Land Rover “ suggests that you change both tyres on front at the same time as it can break the gearbox? Really?
Said to the fitter that it seems stupid to change a perfectly good tyre so thought I’d check on here if anyone had heard of this before? Have been using this tyre shop for years but seems like they may be taking a liberty. Before I change both thought I’d check?

Thanks in advance
Gary

they are correct. if you put the one new tyre on an axle and the difference between tread levels on that axle are too great then it can play havoc with the AWD geometry and sensors.

its the same for all 4WD cars.

back in the days of the Vauxhall Calibra 4x4 you had to change all 4 tyres at the same time as the system could only tolerate a 1mm difference in tread depth between all 4 corners (IIRC)

(28-02-2019 09:35am)RogB Wrote:  they are correct. if you put the one new tyre on an axle and the difference between tread levels on that axle are too great then it can play havoc with the AWD geometry and sensors.

its the same for all 4WD cars.

back in the days of the Vauxhall Calibra 4x4 you had to change all 4 tyres at the same time as the system could only tolerate a 1mm difference in tread depth between all 4 corners (IIRC)

Thanks for information, will order 2

(28-02-2019 08:35am)Waggers Wrote:  Morning all,
Recently had my Evoque serviced at a local garage ( totally trusted and known the owner years), was advised that the Front tyre n/s was wearing on inside and to check the geometry. Thought I may as well get a new tyre and have geometry check at same time, however the fitter at shop said that” Land Rover “ suggests that you change both tyres on front at the same time as it can break the gearbox? Really?
Said to the fitter that it seems stupid to change a perfectly good tyre so thought I’d check on here if anyone had heard of this before? Have been using this tyre shop for years but seems like they may be taking a liberty. Before I change both thought I’d check?

Thanks in advance
Gary

Break the axle my arse! What happens when you fit a space saver tyre on then? That will be waaaay different to the other tyre on the same axle compared to a tyre with new tread and a bald one. Go back and ask the fitter what Landrovers feeling is on their cars going round corners are! Then ask him if he knows what a differential is used for. Better still, ask Land Rover themselves - probably get a different answer as they are not in the business of selling tyres.

Volvo XC 70 and 90 you need to change all four tyres at the same too, causes damage to the diff and transmission but check how many mm tread depth difference the Evoque can get away with because I had a front near side 20” Continental on my 1st Evoque replaced after 8000 miles wear and was told by the dealership it was not an issue, however replacing a high mileage well worn tyre with a new one only on one side WOULD damage the system. There is some leeway in the difference between tread depths.
BTW, the space savers used by LR have the same rolling circumference as the normal tyres / wheels it’s only the width that is different, but you are speed and distance limited on a space saver.

(05-03-2019 09:03pm)XFullFatTim Wrote:  Volvo XC 70 and 90 you need to change all four tyres at the same too, causes damage to the diff and transmission but check how many mm tread depth difference the Evoque can get away with because I had a front near side 20” Continental on my 1st Evoque replaced after 8000 miles wear and was told by the dealership it was not an issue, however replacing a high mileage well worn tyre with a new one only on one side WOULD damage the system. There is some leeway in the difference between tread depths.
BTW, the space savers used by LR have the same rolling circumference as the normal tyres / wheels it’s only the width that is different, but you are speed and distance limited on a space saver.

Do they change the spare tire depending on if you have 18, 19 or 20 inch wheels?
Because it's my understanding it's not the exact same rolling circumference

(06-03-2019 01:21am)wheels Wrote:  Because it's my understanding it's not the exact same rolling circumference

The circumference difference between a 245/45-20 tyre and 225/65-17 tyre is only 0.6%.

With regards to the Evoque space saver, the circumference difference is greater as it's a 155/85-18 which has a circumference difference of 1.1% compared to the 20" and 2.5% compared to 18" but of course you'll be driving slower and only a short distance on the space saver, therefore are less likely to damage the running gear.