Ken_Dickson

Hi all, my first post to the forum so please be gentle!

I bought a very nicely spec?d 2008 (2009 model) 520d SE a couple of months ago and I am VERY pleased with the car, over the moon, or at least I was until last weekend.

When buying the car I specifically checked the tyres as both a negotiating point and to ensure I wouldn?t be hit with a tyre bill too soon. The rear tyres had at least 5mm of tread across the width of the tyre I could see and figured would be good till the end of the year at least.

Tyres were 225/50/17 Bridgesone run flats all round.

To cut a long story short, 5000 miles later I took the car In to have the rear balance checked for a second time (first time was the day afetr purchase) and was shocked to be shown the inside edge of the tread was gone. The rest of the tread still had around 5mm.

I have read through the relevant posts here and it appears that a GOOD four wheel alignment check will help ensure my new rear tyres (225/50/17 Goodyear run flats) last a bit longer. I?ve read about some E60 cars eating rear tyres in 7-8K miles. If it does that I could looking at a £1500 a year bill just for rear tyres. Please can some recommend a centre that can do this work in the Midlands in the UK for me.

Please help.

PS: we?ve also just bought ?her indoors? a 2008 Z4 roadster (E85) on Bridgestone run flats and I think I?ll get that checked out as well to be safe.

Thanks all.
Ken

BMW fanatic

You should ditch the run flats. Second as far as the problem it could be a couple things. Your suspension could have an issue. Most likely its your negative chamber and its way too high. My was at -2.5 after lowering my car. I adjusted it to -1 so the inside of my tires wouldn't wear out as fast. For the most part BMW tires wear out fast on the inside but your case seems a little too fast.

Andrew

sanjsanj

how often are you checking your tyre pressures? and what tyre pressures are you running? I've heard higher pressures reduce uneven wear on the rears...

jaycal3

If you have the sport suspension the negative camber will eat the inside edge of the tires... I would ditch the RFT's but I have asked about the negative camber and have been told by a good friend/BMW Tech that its there for a reason.

KAF

The neg camber IS there for a reason, but if it is beyond the limits it will eat your tyres.

Find an alignment centre near you from the below link and get a full 4 wheel alignment done.

http://www.alignmycar.co.uk/CentreLocator

Higher pressures will change the rear tyre wear pattern by raising the centre of the tread, so transferring wear from edges to centre, but it might cause other handling issues.

Ken_Dickson

Thanks guys.

To respond to some points.

Car is standard SE wheels / suspension, difficult to know about tyre pressure history as I?ve not long bought the car, can?t be exact about current pressure but it?s set as per BMW recommendation and never know how accurate garage gauges are (yes I know I need to get my own). I?ll get into the habit of checking pressures weekly, at least until I know if / how they are changing (after 20+ years in a company car maintenance will take some getting used to again!)

I considered ditching the run flats, mostly because I dislike the vague floaty feeling they give particularly when they are cold, but on balance I think they will stay if I can get decent mileage from them.

The car isn?t going to be driven hard, it wouldn?t have been a 2 litre diesel if I?d intended that. I?ll use the roadster when that urge takes me.

I?m not intending removing the negative camber, just taking down to the lowest end of the recommended range or maybe a tiny bit below. From what I?ve read it is also important to keep the back at around 1 degree more negative than the front.

Still happy to get any more advice on this.

Ken