Tyre Pressures Correct But Middle of Tyre Worn. Advice?

[SebringMan]

Right, I have a BMW M3 of the E46 variety. The rear tyre wear is interesting, but the tyres did come on the car when I bought it. It is on Falken 453s on the rear.

The middle of the tyre is worn to just over 2mm but the outer parts are more like 3.5mm. The tyre pressures are correct (around 35PSI IIRC) and I have checked these both at the petrol pumps and with a digital tyre gauge.

The last owner seemed to think 31PSi was a good pressure to run the rear tyres at, with around 30 up front.

My questions is have others suffered this. It would be nice to know before I start marking the tyre up and playing around with tyre pressures in an attempt to even out the wear.

[E-bmw]

If all you have is 2mm in parts & do not know for sure the history/accuracy of the tyre pressures, I wouldn't bother.

Just ditch them & fir the correct tyres at the correct pressures, keep on top of them every week/fortnight & I suspect the next set will be just fine, if you check (and keep note of) the wear regularly you will see if there are any issues.

[SebringMan]

E-bmw said:

If all you have is 2mm in parts & do not know for sure the history/accuracy of the tyre pressures, I wouldn't bother.

Just ditch them & fir the correct tyres at the correct pressures, keep on top of them every week/fortnight & I suspect the next set will be just fine, if you check (and keep note of) the wear regularly you will see if there are any issues.

Cheers. I suspected it may be to do with the history of the tyres but I figured I may as well ask to save the new tyres going the same way should there be a known fault with the car or tyres .

When replacements are between £130-200 depending on brand it is not simply a matter of 'changing' them (255/35R19 size) . I normally do keep on top of pressures and tyre condition though mind you. Most my cars with new tyres seem to last quite some time.

[E-bmw]

You can possibly beat it, but they will price match, Camskill are pretty good on price.

http://www.camskill.co.uk/m55b0s337p129667/Contine...

[PaulKemp]

I had a VR6 Galaxy that needed front tyre pressure a couple of lbs above the recommended or it would wear the edges first
There is a delicate balance to be found with tyre pressures dependant on your driving style as much as anything, experience and regular checking can give you an understanding of how they wear

[helix402]

That's normal wear for rear tyres on a rwd car.

[E-bmw]

helix402 said:

That's normal wear for rear tyres on a rwd car.

Er, no it isn't.

Centre wear (as per the OP) is indicative of higher than normal pressure over a prolonged period, hence the original question.

[Polywobblydriver]

Hi. Just a newby listening in. The wear pattern could also be a sign of a previous owner 'wheel spinning' the rear wheels to smoke out the rear tyres. Suspension or braking problems usually leave wear that is uneven or on the outer edges, at least I've found that to be the case.

[The Wookie]

Each brand/model tyre will have varying ideal pressures for weight and size. Sometimes a manufacturer will recommend a pressure for ride and handling purposes (or other aspects like fuel consumption) despite less than ideal wear.

If you're not varying drastically from recommended pressures then I'd say up to you to determine what's important to you

[Mr2Mike]

E-bmw said:

Er, no it isn't.

Centre wear (as per the OP) is indicative of higher than normal pressure over a prolonged period, hence the original question.

Radial tyres don't wear in the centre unless grossly overinflated.

[E-bmw]

Mr2Mike said:

E-bmw said:

Er, no it isn't.

Centre wear (as per the OP) is indicative of higher than normal pressure over a prolonged period, hence the original question.

Radial tyres don't wear in the centre unless grossly overinflated.

As I said.

[Mr2Mike]

E-bmw said:

As I said.

You said "higher then normal pressure". 5 or 10 psi isn't going to do much apart from reduce grip; you can go significantly over the 'normal' pressure and still not wear out the center of the tread with a radial. Crossplies are a different matter.

[E-bmw]

e46 M3 - rear tyre section 255.

5 or 10 psi over for a sustained period with even a reasonably heavy right foot will absolutely produce this wear pattern.

[PaulKemp]

Have a look at the car tyre bible (online)
There is a lot to consider and the bible helps you have an understanding of amongst other useful stuff tyre wear
In my experience and because I am an enthusiastic driver, different wear patterns signify different problems.
As I said earlier I had a car that needed a few more psi to wear even, I have friends who race and tyre pressure is often different on all 4 (at the start of the race) the idea being that they will all be the correct pressure once they warm up (much more obvious when racing on short ovals).
Don't rule out dropping a couple of psi out and seeing what happens, don't however try to even up the tyre wear by underinflating the tyres, you'll just run on the edges

[Sheepshanks]

Mr2Mike said:

E-bmw said:

Er, no it isn't.

Centre wear (as per the OP) is indicative of higher than normal pressure over a prolonged period, hence the original question.

Radial tyres don't wear in the centre unless grossly overinflated.

My old Merc C270, that I mainly used for motorway cruising, wore the centres of the rear tyres and I ran them at the minimum stated pressures.

I did wonder if higher pressure would have been better and perhaps the tyre was slightly losing shape at speed.

[SebringMan]

Sheepshanks said:

My old Merc C270, that I mainly used for motorway cruising, wore the centres of the rear tyres and I ran them at the minimum stated pressures.

I did wonder if higher pressure would have been better and perhaps the tyre was slightly losing shape at speed.

Going off the Car Bible it turns out the way I have is normal for wheels that are on the wide side and on the rear of the car.

[helix402]

Not sure what the car bible is. As I said at the start of the post your wear is normal despite what some others have said. My answer is based on working on BMWs since 1994 and owning a few (I am qualified BMW Technician).

[exitwound]

Mr2Mike said:

E-bmw said:

Er, no it isn't.

Centre wear (as per the OP) is indicative of higher than normal pressure over a prolonged period, hence the original question.

Radial tyres don't wear in the centre unless grossly overinflated.

Yes they do, and the wider the tyre the more obvious it is.

My Corvette has 295/50x16's (10" wide wheels all round) on the back and despite running about 30psi, that wear pattern still happens. If I drop the pressure any lower, then you can feel the sidewall really flexing when cornering and the handling suffers badly too, kinda reminiscent of my old Mk1 GT Cortina on its 6.00x13 crossplies which to be fair was a lot of fun back then and taught me such a lot about controlling a drifting car.

At 32psi all round (255 on the front), it drives very well on the twisty stuff wet or dry, so the wear is a cross I need to bear as difficult as it is to find tyres in that size these days.

[GreenV8S]

exitwound said:

Yes they do, and the wider the tyre the more obvious it is.

It may be that what you're seeing isn't the tyre circumference increasing, but the lower pressure giving a longer contact patch with more slip at the leading and trailing edges which would lead to wear in the center. (I suspect it's also that longer contact patch which is messing up the handling as you describe.)

[exitwound]

GreenV8S said:

exitwound said:

Yes they do, and the wider the tyre the more obvious it is.

It may be that what you're seeing isn't the tyre circumference increasing, but the lower pressure giving a longer contact patch with more slip at the leading and trailing edges which would lead to wear in the center. (I suspect it's also that longer contact patch which is messing up the handling as you describe.)

That could be it, ..but if I take it up much higher, the car drifts easily wet or dry and I can smoke the rears easily from a standstill which on occasion I do for the hell of it!) I do use 35psi for the motorway though (450mile trips to Goodwood). 32psi works out ok, been that way on BFG, Cooper and Maxxis tyres none of which are rated highly anyway, but they're cheap and have deep treads.