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Tyre sizes

Discuss your latest mods or ideas, and anything to do with the BMW X5 (E53).
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Themoog2
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Tyre sizes

Post by Themoog2 » Tue Jun 27, 2023 6:18 am

Just putting it out there..
I have 315 35 r20 rear and 275 40 r20 tyres on. Is it possible to go up in diameter (tyre height) to increase driver comfort ie 315 40’s and 275 45s or whatever?
Has anyone done this? Im contemplating getting new tyres soon and was just wondering although if I got top quality standard size tyres I suppose it would make a difference anyway.
I did have a Cayenne which had 22”s with rubber band tyres on it so I swapped them back to the standard wheels and tyres and I drove so much better.

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X5Sport
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Tyre sizes

Post by X5Sport » Tue Jun 27, 2023 6:49 am

Changing the sizes up will change the rolling diameter and throw the Speedo out. You may also struggle with clearance in the arches, particularly when turning. If you go down to 19” wheels that will help. My 19” winter set are noticeably smoother than the 20”. You could also try coming off runflats as those have softer sidewalls too.

19” wheels do look a little ‘lost’ on the X6 though. Spacers will improve the look.

The other issue is maintaining the correct match front to rear if you increase the sidewall height on 20”. Get that wrong and it’s goodnight transmission!
:ant: Never anthropomorphise computers. They hate that.

Themoog2
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Tyre sizes

Post by Themoog2 » Tue Jun 27, 2023 7:47 am

Agreed.
I think I’ll just stick with standard.

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