Irreparable puncture in rear tyre. Other tyre has 5.5-6.0mm tread left. Replace one or both?

GravyMonster

GravyMonster

GravyMonster

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Just got back home and got an alert on my phone about low pressure in my rear left tyre. Go out and check and sure enough, there's a screw sticking out of it about 1.5-2cm from the inside shoulder. I'm 99% sure it's not repairable.

The tyres have only done ~5000 miles and have at least 5.5mm of tread on them measured using my depth gauge. Do I replace both (£415) or one (£207)? What would you do motors?

For reference, the car is an M240i xDrive on MPS4S
 
Have you gone down to a local tyre place and asked their advice? I'd be checking if it was repairable first before just splashing out on a new tyre!
 
Put a pic up, I’ll tell you if it’s repairable or not.
Also, why replace the other one?
 
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Maccy said:
Have you gone down to a local tyre place and asked their advice? I'd be checking if it was repairable first before just splashing out on a new tyre!
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Just got back. Local Just Tyres place said it's too close to the shoulder and isn't repairable.
JonRGV250 said:
Also, why replace the other one?
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Most things I've read before suggest having mis-matched tread depths on an axle - especially an xDrive - is not good. In this case it'd be a ~3mm difference across the tyre as new MPS4S have 8mm from new.

Happy to be proven wrong though, which is why I started this thread :)
 
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GravyMonster said:
Most things I've read before suggest having mis-matched tread depths on an axle - especially the driven wheels - is not good. Happy to be proven wrong though, which is why I started this thread :)
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What does it say in the owner's handbook / idrive owners help under either the Driver Stability section ref (xdrive) or the section on tyres?

Assuming there's no specific mention then I would only be looking at replacing a single tyre.
 
Kenai said:
Ask on a BMW owners group somewhere and you'll repeatedly be told that even the most marginal difference in tyre circumference will cause all BMW xDrive systems to explode into a thousand pieces within 10 minutes of driving away from the tyre fitter.
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I assumed as much.
 
GravyMonster said:
Just got back. Local Just Tyres place said it's too close to the shoulder and isn't repairable.

Most things I've read before suggest having mis-matched tread depths on an axle - especially an xDrive - is not good. In this case it'd be a ~3mm difference across the tyre as new MPS4S have 8mm from new.

Happy to be proven wrong though, which is why I started this thread :)
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Do you have a full size spare?
 
lordrobs said:
About 0.8% difference in circumference... I'd be losing sleep ;)
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Alcohol will help :)
SPArton said:
How many instances of xDrive failure have we actually seen caused by threads mismatching
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If you believe Reddit, then the UK roads are scattered with stranded xDrives with grenaded diffs.
Terminal_Boy said:
Do you have a full size spare?
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Nope. Just tyre goop.

I was leaning toward just getting 1 replaced, but wanted a head check to see if I was just being tight. Thanks guys.
 
Most tyre manufacturers don't recommend more than 2mm tread difference, I don't know about xDrive but a lot of systems like 4Motion recommend no more than ~2mm difference on an axel.

EDIT: According to several posts by people who seem to know what they are talking about xDrive max tolerance is 1% rolling circumference rather than a specific mm.
 
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All sorted now. I replaced both in the end, and kept the good tyre just in case it happens again soon, as @mattyg suggested.

The offender:

GdumCsp.png
 
GravyMonster said:
Just got back home and got an alert on my phone about low pressure in my rear left tyre. Go out and check and sure enough, there's a screw sticking out of it about 1.5-2cm from the inside shoulder. I'm 99% sure it's not repairable.

The tyres have only done ~5000 miles and have at least 5.5mm of tread on them measured using my depth gauge. Do I replace both (£415) or one (£207)? What would you do motors?

For reference, the car is an M240i xDrive on MPS4S
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From memory the PS4S come with 7.2mm.

xDrive cars can be really fussy with changing tyres but it’s probably worth doing just the one to begin with.


Edit: irrelevant :P
 
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