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[Nifty]

One of the first things I addressed when I got my car was the runflats which I replaced with a set of Conti DWS. 225/40R18 up front and 255/35R18 in the rear. I went with these for a variety of reasons, one of them being the supposedly excellent tire wear. 18,000 miles later im surprised to find what I would call abnormal tire wear on both rears. The the shoulders are around 6-7/32" but the centers are almost down to the wear bars at about 3-4/32".

Normally I would think this would indicate that the tires are overinflated, but if anything they have been under optimum pressure for most of their life. I have all four corners at 38psi cold pressure (And I make sure to adjust during the warmer months) and the fronts don't show any sign of abnormal wear.

I understand that I'm not going to get the 50,000 miles of treadlife on a tire that cannot be rotated and on the drive wheels, but I'm perplexed as to why the tires are wearing as they are. Anyone have a similar experience?

Edit: I checked to make sure, and my door does in fact show 36psi up front and 39psi in the rear as recommended pressure

[jbenington86]

Originally Posted by Nifty

One of the first things I addressed when I got my car was the runflats which I replaced with a set of Conti DWS. 225/40R18 up front and 255/35R18 in the rear. I went with these for a variety of reasons, one of them being the supposedly excellent tire wear. 18,000 miles later im surprised to find what I would call abnormal tire wear on both rears. The the shoulders are around 6-7/32" but the centers are almost down to the wear bars at about 3-4/32".

Normally I would think this would indicate that the tires are overinflated, but if anything they have been under optimum pressure for most of their life. I have all four corners at 38psi cold pressure (And I make sure to adjust during the warmer months) and the fronts don't show any sign of abnormal wear.

I understand that I'm not going to get the 50,000 miles of treadlife on a tire that cannot be rotated and on the drive wheels, but I'm perplexed as to why the tires are wearing as they are. Anyone have a similar experience?

Well question #1: Doesn't the inside of the door say 32psi front 35psi rear? If you are over inflating your tires it is creating more wear on center of the tread.

Question #2: Do you break your wheels loose on take off? If that's the case why are you worried about tread life

I have the Goodyear LS-2 RFT with horrible tread life rating (30,000 miles) and I have driven over 43,000 miles on them by keeping the inflation exactly as BMW prescribes and not spinning the tires on take off (except for every once in a while ) I do plenty of "spirited" driving as well.

[Gary@TireRack]

Originally Posted by Nifty

One of the first things I addressed when I got my car was the runflats which I replaced with a set of Conti DWS. 225/40R18 up front and 255/35R18 in the rear. I went with these for a variety of reasons, one of them being the supposedly excellent tire wear. 18,000 miles later im surprised to find what I would call abnormal tire wear on both rears. The the shoulders are around 6-7/32" but the centers are almost down to the wear bars at about 3-4/32".

Normally I would think this would indicate that the tires are overinflated, but if anything they have been under optimum pressure for most of their life. I have all four corners at 38psi cold pressure (And I make sure to adjust during the warmer months) and the fronts don't show any sign of abnormal wear.

I understand that I'm not going to get the 50,000 miles of treadlife on a tire that cannot be rotated and on the drive wheels, but I'm perplexed as to why the tires are wearing as they are. Anyone have a similar experience?

My rears always wear away in the middle first and I run the recommended 36psi.

[jbenington86]

Originally Posted by maxnix

Recommended tire pressures vary depending on load and speed.

RTOM!

Yes, well obviously over inflating isn't working because you have a ton of wear in the middle compared to the edges. Unless you are hauling weights or sandbags I highly doubt you need to increase the pressure in your tires. Or you could increase the pressure some more and wear them out faster.

[Tom K.]

[quote=jbenington86;9018323]Well question #1: Doesn't the inside of the door say 32psi front 35psi rear? If you are over inflating your tires it is creating more wear on center of the tread.
[quote]

32/35 is the recommended normal pressure for a 128i, but it's 36/36 for Nifty's 135i. And the full load, high speed rear recommended pressure is 42 psi for both 128i and 135i.

I run the rear DWS tires on my 128i at 38 to improve the steering feel and after 10,000 miles, the rears are showing 7.5~8.5/32" depth across the tread, so I doubt the tires are overinflated.

I did have an alignment done about 4,000 miles prior to mounting the DWS - I wonder if that could be an issue.

Tom

[jbenington86]

[QUOTE=Tom K.;9018542][quote=jbenington86;9018323]Well question #1: Doesn't the inside of the door say 32psi front 35psi rear? If you are over inflating your tires it is creating more wear on center of the tread.

32/35 is the recommended normal pressure for a 128i, but it's 36/36 for Nifty's 135i. And the full load, high speed rear recommended pressure is 42 psi for both 128i and 135i.

I run the rear DWS tires on my 128i at 38 to improve the steering feel and after 10,000 miles, the rears are showing 7.5~8.5/32" depth across the tread, so I doubt the tires are overinflated.

I did have an alignment done about 4,000 miles prior to mounting the DWS - I wonder if that could be an issue.

Tom

If it is an alignment issue would it cause excessive tread wear in the middle on both rears? I'm assuming both rear tires have the same issue.

[BrokenVert]

It's called a 255 tire on an 8.5" wheel. The tires sidewalls don't sit straight, they are constantly flexed Inward due to the fact that the tires is wider than the wheel so that more pressure is placed dead center on the tire, causingthat area to wear more

All of our tires wear like this. It sucks but 18K is pretty solid out of a set of rears.


Edit: just ran the math and 255mm is 9.8 inches. Way wider than the wheel it's on.

[jbenington86]

Originally Posted by BrokenVert

It's called a 255 tire on an 8.5" wheel. The tires sidewalls don't sit straight, they are constantly flexed Inward due to the fact that the tires is wider than the wheel so that more pressure is placed dead center on the tire, causingthat area to wear more

All of our tires wear like this. It sucks but 18K is pretty solid out of a set of rears.

Also another possible reason but I think you should get alot more than 18k out of a set of rears.

[BrokenVert]

Originally Posted by jbenington86

Also another possible reason but I think you should get alot more than 18k out of a set of rears.

Not with a car that has 300lbft of instant torque through 3/4 of the powerband. That kind o power puts a lot of stress on a tire. The stock efts typically only last 15k and I've gotten 23K out of a set of PS2s but that was mostly highway.

You have a 128 and your tires last longer, it's just the nature of the beast.

Also the OP has DWS which are the Conti extreme summer tires right? That class of tire is basically an Rcomp with slightly better treadwear

[jbenington86]

Originally Posted by BrokenVert

Not with a car that has 300lbft of instant torque through 3/4 of the powerband. That kind o power puts a lot of stress on a tire. The stock efts typically only last 15k and I've gotten 23K out of a set of PS2s but that was mostly highway.

You have a 128 and your tires last longer, it's just the nature of the beast.

Also the OP has DWS which are the Conti extreme summer tires right? That class of tire is basically an Rcomp with slightly better treadwear

I highly doubt everyone uses all 300ft/lb all the time while driving. If you do then you deserve to shell out for tires 1-2 times a year. That also just voided this thread. 135i drivers should not complain about tread wear because "it's just the nature of the beast." I have also seen 128i drivers only getting 20k out of their tires must be all that torque or could it be spinning tires autocross etc?

[BrokenVert]

Originally Posted by jbenington86

I highly doubt everyone uses all 300ft/lb all the time while driving. If you do then you deserve to shell out for tires 1-2 times a year. That also just voided this thread. 135i drivers should not complain about tread wear because "it's just the nature of the beast."

That's a true statement. But without owning an N54 you just can't understand how easy it is to accidentally unleash the car. And I mean that sincerely. Just passing somebody on the highway can do it.

And it is abosolutly the nature Of the beast. OP bought tires with a short lifespan and expected them to last.

But I think the OP is also complaining about the tires wearing more in the middle. It's just the way that the car eats tires

[jbenington86]

Originally Posted by BrokenVert

That's a true statement. But without owning an N54 you just can't understand how easy it is to accidentally unleash the car. And I mean that sincerely. Just passing somebody on the highway can do it.

And it is abosolutly the nature Of the beast. OP bought tires with a short lifespan and expected them to last.

But I think the OP is also complaining about the tires wearing more in the middle. It's just the way that the car eats tires

Also you guys can't rotate your tires like us 128i folks can.

I did notice something weird with my tires 90% of the tread wear happened within the first 30k miles and the last 13k miles I have seen virtually no tread wear on them. They have stayed about 1/32" away from the wear bar for 13k miles. Looks like they will last through the summer.

[Nifty]

Thanks for the responses everyone. This IS my first RWD car, and maybe my expectations of treadlife were a bit lofty. Once agian, I never expected them to last 50k miles, but at the same time I didn't expect them to be this worn at 18k either. More than anything, the uneven treadwear is what concerns me.

If I was doing burnouts and constantly letting the tires slip, I would expect tire wear and mileage like this, but while I do drive the car pretty spiritedly I do not 'abuse' them. If this is the nature of the beast as some have suggested, so be it, you've gotta pay to play. The reason for posting was to get some feedback as to what if anything I have been doing wrong so I can correct it in the future if possible.

I need to look again but I THOUGHT, the recommended pressures (on the door) are 36psi front and 39psi rear. I'll have to check after work today. If I have been running over recommended pressure then I'll just take it as lesson learned.

[jbenington86]

Originally Posted by Nifty

Thanks for the responses everyone. This IS my first RWD car, and maybe my expectations of treadlife were a bit lofty. Once agian, I never expected them to last 50k miles, but at the same time I didn't expect them to be this worn at 18k either. More than anything, the uneven treadwear is what concerns me.

If I was doing burnouts and constantly letting the tires slip, I would expect tire wear and mileage like this, but while I do drive the car pretty spiritedly I do not 'abuse' them. If this is the nature of the beast as some have suggested, so be it, you've gotta pay to play. The reason for posting was to get some feedback as to what if anything I have been doing wrong so I can correct it in the future if possible.

I need to look again but I THOUGHT, the recommended pressures (on the door) are 36psi front and 39psi rear. I'll have to check after work today. If I have been running over recommended pressure then I'll just take it as lesson learned.

Honestly I would play around with the tire pressure to see what kind of changes it makes to tread wear. You might not get the extreme performance your looking for but you might get a more even wear and get some more miles out of the rubber. When I put winter tires on my 370Z I could tell from the first 100 miles the suggested tire pressure was higher then it should be for the blizzak tires I bought. The tread of all four tires about 1 inches on each side of the tire was not even contacting the ground which in the long run would make the center wear out extremely fast. So I had to under inflate the tires by about 3-5lbs from what is suggested and the tires are in great shape with no excessive wear anywhere.

[Tom K.]

Originally Posted by jbenington86

Also you guys can't rotate your tires like us 128i folks can.

Wish I could - but my ZSP 128i has the staggered wheel/tire sizes. So I wound up discarding the OEM front RFTS with half the tread remaining because I couldn't find matching rears at a reasonable price.

I think BrokenVert has the right idea as Nifty's tires seem to be seriously oversized.

Tom

[Nifty]

Originally Posted by Tom K.

Wish I could - but my ZSP 128i has the staggered wheel/tire sizes. So I wound up discarding the OEM front RFTS with half the tread remaining because I couldn't find matching rears at a reasonable price.

I think BrokenVert has the right idea as Nifty's tires seem to be seriously oversized.

Tom

What BrokenVert says makes sense, I dont believe the tires are "seriously oversized" since the originals are 245's and going to a 255 adds less than .4" to tread width.

That said though, I'll play around with some pressures lower than recommended to see how it will affect tread wear.

[jbenington86]

Originally Posted by Nifty

What BrokenVert says makes sense, I dont believe the tires are "seriously oversized" since the originals are 245's and going to a 255 adds less than .4" to tread width.

That said though, I'll play around with some pressures lower than recommended to see how it will affect tread wear.

I'm no tire expert but everything I can find on over inflation says pretty much the same thing no matter where I look it up.

"Over-inflation can be a problem, too. An over-inflated tire rides on just the center portion of the tread. The smaller contact area means reduced grip on the road, leading to a harsh ride, handling issues (such as steering and stopping problems) and increased wear on tires and suspension components."