[gfunk]

hey all,

I was planning to swap the tyres on my F31 330d XDrive in the new year but I've got a very slow puncture on front drivers side which on inspection at the garage today is a tiny hole on the inner sidewall so not repairable and it looks like I'll need new tyres.

Am I right in saying I'll need to replace them all at once as they are all pretty much worn evenly(ish)?

The car came with staggered 20" CS replicas, I think they are from CM Wheels but not 100% sure, with the following size tyres but the front is pretty stretched and gives the rim no protection at all (see pic)

Current setup -
Front - 225/35R20 Y90
Rear - 275/30R20 Y90

I'd like to go wider on the front to 235 or even 245 but would appreciate any advice on the setup as I know Xdrive is more sensitive but wasn't sure if that was more the overall diameter rather than width?

cheers in advance.

[StuieUK45]

to note:
I have Falken non run flat all round on my F30 335d (20")...
The driver rear had nail in shoulder, so had to replace the tyre....
Have replaced with a Falken tyre, but tread is new on 1, not new on the others...
I had reset the tyre sensor thing, and have driven 200 miles since, with no issues or errors

Just giving info on my setup

[HighlandPete]

Originally Posted by gfunk

I'd like to go wider on the front to 235 or even 245 but would appreciate any advice on the setup as I know Xdrive is more sensitive but wasn't sure if that was more the overall diameter rather than width?

cheers in advance.

Remember that when we change width, we also change the diameter, as part of the aspect ratio.

[gfunk]

Originally Posted by HighlandPete

Remember that when we change width, we also change the diameter, as part of the aspect ratio.

Yes, aware of that and from trying various online tyre size calculators it looks like the setup that came on the car is actually +1.1% so changing to a 235/35 front would actually match the 275/30 rears better and bring it to 0%.

[APJ]

i had a similar problem, but after checking some ratio i found that someone had put on the forum that 235's are a better balance for the transfer box if you have 275's on the rear

[HighlandPete]

Originally Posted by gfunk

Yes, aware of that and from trying various online tyre size calculators it looks like the setup that came on the car is actually +1.1% so changing to a 235/35 front would actually match the 275/30 rears better and bring it to 0%.

Ah, I wasn't thinking 275 on the rear, but standard 255 section. Should pay more attention to all the comment.

[G50]

Originally Posted by StuieUK45

to note:
I have Falken non run flat all round on my F30 335d (20")...
The driver rear had nail in shoulder, so had to replace the tyre....
Have replaced with a Falken tyre, but tread is new on 1, not new on the others...
I had reset the tyre sensor thing, and have driven 200 miles since, with no issues or errors

Just giving info on my setup

Depending on the tread depth of your 3 older tyres you could have an issue further down the line if the difference between old and new is too high. Any issue would be unlikely to show itself in just 200miles.

My last unrepairable puncture I measured the tread depth on my existing tyres and found a part worn on ebay same brand/model tyre with same tread depth as the existing tyres. Helps if your tyres are OEM or a popular brand/size.