Tyre Wear - not Stag

[Gareth Evans]

My everyday car is a 2003 BMW 525d touring
I bought it when it was 8 months / 12000 miles old, and the tyres (Michelin Primacy) were all about half worn so I assumed they were the original tyres.
The rears lasted another 12000 miles, fronts another 20000.
When I replaced them it was with Michelin Primacy again - These lasted a similar time (23000 rear, 30000 front).
But the last set of rears (Michelin Primacy again) only lasted 12000 miles. A bit poor I thought, so had 4 wheel alignment done by the local body shop. It was a little out on all corners but not a whole lot.
The car has just failed it's MOT on rear tyres. They have done 6500 miles. One of those tyres was the original spare unused before I put it on last May - so should have been exactly the same as one that did 24000 miles. The wear is nice and even right across the tread pattern.

Has anyone got any idea of what could be causing such poor performance?

Many thanks,
Gareth

[Goldstar]

Suspension bushes? Mine need changing at the front (03 530d) but my tyre wear has been excellent. First set of rears changed at about 30k and I have just put the 4th, actually probaly the 5th, set on the back (145k) always Primacys and either I have been lucky or there is something amiss with your car or the tyres? Original spare probably degraded due to age and therefore wear was accelerated? You could, of course, stop smoking it away from the lights.....

Paul

[Guest]

Wow.....as a fellow BMW owner I am seriously impressed that your rears do 20k miles let alone 30k!

[cjp]

Gareth, In my experience (4th BMW so just realized I have owned as many Roundels as Triumphs), they are incredibly sensitive to poor alignment and will chew up tires/tyres in no time if they are out even a tiny bit. The modern multi-link rear suspensions are complex and fully adjustable in what appears to be 4 dimensions, so much more than a basic static fore and aft alignment is required. I'd suggest your local body shop might not be the best place to get this done. Try an independent BMW specialist if the dealer is too pricey (or arrogant)!

The tires on my M3 are Pilot Sport and $500 a corner, so I do spend the 100 bucks to get it done "properly" once a year, and so far I'm on track for 20,000 miles on both the snow and the summer rear tires, and they do get hammered hard. 30K would be a minor miracle...

On a related note, I very rarely buy extended warranty or insurance on anything, but took one look at the aspect ratio on the M3 tires and signed on the dotted line. I had two brand new replacement tires due to close encounters with potholes, so that paid for itself! Unfortunately it has now timed out... I wish the roads in the snow-belt states were half as good as the UK roads. Some of our potholes could eat a Fiat 500 whole.

Chris

[4x4]

Some of our potholes could eat a Fiat 500 whole.

Chris

Don't worry - our roads are going downhill fast................

[Goldstar]

Wow.....as a fellow BMW owner I am seriously impressed that your rears do 20k miles let alone 30k!

Yours is an M3 Ian

[Gareth Evans]

Thank you all for your replies.

It looks like a trip to the dealers for me. Yes they are more expensive but if it cures the problem then it will pay for itself. And it sounds like I ought to take Chris's advice and have it checked every year as the roads around here are terrible - more like farm tracks.

The old spare did wear out slightly quicker than the new tyre on the other side, so degradation is a factor. But I'll be surprised if I get another 1000 miles out of the newer one so it'll last only 7500 miles.


-- Gareth

[ChasR]

I would recommend someone else for the alignment checks, but almost everyone I know is miles away for you!

www.wheelsinmotion.co.uk - They seem to have a good reputation. They are based in London.
http://www.centergravity.co.uk/ - They are not cheap, but they can setup a road car superbly. Based in Atherstone, Warwickshire.

[Guest]

Yours is an M3 Ian

More like an M£ Paul

Chris, which M3 do you have? I have had M3's for about 10 years and don't know of anyone here who gets more than about 12k miles from a set of rear tyres. I know that the American M3 spec is different to the UK - slightly de-tuned - so am now wondering if the rubber compound is different for the tyres too?

[cjp]

Ian, it's a 2009 E90 with DCT. It has the standard 414 HP V8, which I think is the same configuration worldwide for the E9x series. It was the previous generation that the US only merited a detuned version. Tires here do seem to last a bit longer, so I suspect the compounds might be different to compensate for the vast amount of concrete highways we have. You've got me worrying now that I only checked the tread depth on the fronts before packing 'em away. Will have to dig one of the rears out from the tire cosy and check more carefully. I've got about 12K on the summers after last season.

I know that there is a BMW to Stag rear axle transplant from the previous generation, but I keep thinking that if an E9x drivetrain can fit under the 1 Series, it should fit under the Stag complete with the V8! I wonder if anyone has tried that particular combination? Not my cup of tea, as I've spent so much energy on keeping my Stag as close to original as I can, but I would love to try the result. Folks here stuff modern Corvette/Mustang/Charger running gear under anything that moves, with some success.

[Guest]

I thought it might be the E9x you had. I am not sure how similar the Europe / USA spec's are, and what I was saying is based more on E36 / E46 versions. Saying that, from what I have heard on forums the E9x tyre wear isn't significantly different over here.