Removing Runflats - 125i M Sport

[bodhi]

Hi All,

It's reached that unpleasant part of the year where the 125i is about the need new tyres - after 40K of having my fillings jostled by the OEM Bridgestone Runflats I've decided it's time to get rid and put some normal tyres on - I have family who work for Michelin so will have to go down this route, so was looking at the new Pilot Sport 4's, but from the looks of things they aren't available in the default size for rears of an E82 M-Sport - 245/35 R18's. I've noticed I can get 255/35 R18's, has anyone ever tried going for 225/40 on the front and 255/35 on the rear?

Am I likely to encounter any issues with rubbing? It has 208M's on currently.

[bodhi]

Speedo is already out by 10%, was hoping this would bring it a bit more in line

[bodhi]

After a quick chat with Black Circles they suggested that the 225/255 combination will be a good fit for the car, so I have 4 Michelin Pilot Sport 4's on order to be fitted on Saturday.

This has led me to the next question - the spare wheel. I've been generally advised to go down the tyre sealant route, but from the looks of things the standard gunk makes the tyre useless after it's been used - has anyone tried Ultraseal?

http://www.ultrasealgb.co.uk/site/

[bodhi]

Just thought I'd update, had 4 x Michelin Pilot Sport 4's fitted on Saturday, going for the 225/255 option as mentioned. Pretty sure I brought someone else's car back from ATS, these tyres are an absolute revelation. Ride is completely transformed, rather than crashing over everything, it glides, even over those viscous small black and yellow speed bumps that used to induce much wincing. Grip seems even better than it was before, tyre noise is massively reduced, and wet grip is astonishing. did 100 miles in the monsoon on Monday, zero issues with standing water whatsoever.

I have had to take the car back to ATS as the front right was losing pressure, turns out the tyre wasn't seated properly. It was sorted with no quibble, so no complaints.

Best thing I've ever done in a car tbh.

[bodhi]

I went up 10mm in both fronts and rears, so haven't had any warning lights or other adverse affects. Well I say that, for the first 4 days I was getting Tyre Pressure warning lights, but that was mostly because ATS hadn't seated the front right tyre properly. Wish I'd known that before I jumped on the M6 to go to work, but hey ho. The effects I have noticed though:

- Ride is night and day better
- Traction is vastly improved
- Speedo is now accurate
- I don't have to avoid speed bumps any more

Only slight adverse effect I have noticed is MPG has dropped from just over 30 to 28, however that happened this time last year, so I am unsure if it is the tyres, or a temperature/winter fuel issue.

It's also had the additional effect that I am no longer thinking about the next car - the ride was getting pretty unbearable at times, and doing 20k a year it was less than ideal, but with the PS4's, it is absolutely fine.