20" tire tread depth goes fast

[solrac6262]

psi are ok 35 32 I think

[Couper93]

Speed is causing the wear. Mine are doing the same thing...I have Michelins. I took mine in to discount tire and they said I was spinning them....really?
After I relayed that spinning was impossible, they took pictures and set to Michelin rep...I am waiting to hear from them.

[fast4d]

wear in the middle doesn't point to alignment. unless you have some raised or scalloped edges at the sipes/grooves.

what's the tire pressure?

the middle will always wear fastest. especially on the rear tires.

[ard]

Originally Posted by Mitch P.

OK I deserve that. A bit harsh though ARD - aren't you from the M5 board?

None of these, even the MX5 is an excellent turn-in vehicle. Neither is my M5. An E30M3 though...different story.

Excellent was an incorrect term that I used. I will say this - I meant it relatively speaking. Compared to my 4.8is - the turn in is BETTER. Not excellent. I should go back and edit that...might do it later.

I agree on dialing out the toe - this is what I had to do with the 4.8is to reduce excessive tire wear. I was asking more for gathering information...not inducing a laugh at my expense.

So, let's get back to my original question - will it reduce the turn in to a point where it's noticeable? Most likely not, but seeing as how I was annoyed at the 15kmi tire wear on the 4.8is, I will be especially annoyed at that same tire wear on expensive run flats.

Respectfully,

Mitchell

OK, so I did tee off on you a bit.... The whole 'we set toe to help turn in' was an issue over on M5board too... drivers that would ever see a track or know what turn in is, were wasting money and tires for something that isn't really much of an issue for them.

I guess I should have said "try it and see how it works for you". I'll submit that after getting 30-35k miles on your tires, you'll like the turn in just fine.



A

[Aviator]

I have the same problem as well. The middle of the rears wear out amd am in my 4th set of tires.
I run Michelin tour lats.
Would like to hear from others who have the same tire (stock size 20" sport) What PSI do do run if you have even tire wear?

[ard]

Toe, toe, toe

[Aviator]

Originally Posted by ard

Toe, toe, toe

Ard, I did read the entire thread. Yes, I have had it checked by BMW and as you said was told all was well.
What I cant understand is how "just the center" portion of the tire can be wearing out due to toe in error. Now, I am not an engineer, so if you could dumb it down and explain please.

[ard]

what toe is it set to?

you know that I harp on "don't trust BMW to say "OK"..their range is too large"

Excessive toe will accelerate the wear of a tire. Not just on the inner or outer edge, but just overall- whatever the wear will be for a given alignement, MORE toe will mean MORE wear.

Now, most alignments are biased- the rear is cambered with the top in, so the inner edge has more pressure- AND excessive toe will accelerate this wear pattern... but if your alignment is on the minimum for camber and maybe a bit over inflated, then maybe you see mid tire wear.

post up the bmw alignment numbers. If they didnt give you the print out, call the SA and have them fax it- should be in the file with the work order.

A

[LVR]

I've had this problem previously. Photographed it and spoke at length with tyre company head techies. They said...

1.Once you start to get a wear pattern in the tyres regardless of its' cause, the tyre will continue to wear in that spot even if you remove the cause. ie if they are overinflated the centre will wear. Each time they heat up that point continues to wear quicker even if you drop the pressures back and will continue to do so for the rest of the tyre life. Same applies to alignment.

2. The X5's are VERY sensitive to weight in the suspension geometry. Both the tyre tech (who was independent) and the BMW tech both confirmed that weight in vehicle affected the suspension geometry setup during alignment and subsequent driving. One of the first questions they asked me was do I tow anything...

3. I had an E53 X5 4.8is and the auto leveling suspension kept dropping whilst moving which changed the geometry enough to chew out the rears.

4. High speed running or heavy loads can cause the tyre to overheat and a starting point high pressure can cause centre wear once tyres are overheated. I considered his suggestion of nitrogen in the tyres due to the fact that the tryres don't change in temp somewhat of a gimmick however recently I'm hearing more people do it through tyre shops for low profile tyres on big SUV's, with success.

5.Toe in typically results in feathered edges and a saw tooth pattern on either the inside or outside of the tyre.

I've had a number of X5's and an E60 now all with different wear characteristics. I make it a habit of getting the dealer to check the settings when I have NEW tyres on, and then a check at every 6 months.

Cheers

J

[ard]

Originally Posted by LVR

5.Toe in typically results in feathered edges and a saw tooth pattern on either the inside or outside of the tyre.


J

While this is true for toe wildly out of spec, I am referring to toe at the outer bounds of BMW spec.

I've heard what you posted oft repeated- "oh it can't be toe since toe will __________". Right.

We are pissing in the wind without actual alignment numbers posted.

Also, nitrogen is a scam- please don't fall for it. Remember people that sell tires, own tire shops actually believe it- but it is, in the end, a scam. PV=nRT, all gases expand when heated.

A

PS I've been able to alter wear patterns by changing pressure... still trying to understand that theory.