Suggestion for a car with staggered, toe out tires

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2nd gen IS250 (2008), RWD Front tire is 225/40-18, Rear tire is 255/40-18. The rear last about 60k miles which is good, the front only 30k (factory, 150 UTQG) to 45k (Kumho LX Platinum, 600 UTQG). I've already done a zero toe alignment (the only adjustable setting on this car) on the front at a tuner shop, and the car is still the front wearing faster than I want it to. I am going to buy a new set of front again and am wondering what should I buy this time around. Should I: 1) Buy the longest trend life warranty (which usually correlate to a longer life), like Kumho LX Platinum, again at around $120-140 ea? My "concern" is these tires sacrifice fuel economy for durability. Traction of the LX Platinum seems to be good enough, but fuel economy seems to take a hit (around 1 mpg, 29 instead of 30mpg now). I don't think I will get to use these warranty because of the toe out wear that comes with the car, but usually if they have longer warranty they can last longer. My choice right now is any reputable tire that has >45k warranty for less than $130 shipped. 2) Buy the tallest trend block tire (i.e. 10.5/32" instead of the 9.5/32" to the standard 10/32"), because there are more meat to wear out in a "misaligned from factory" car. They seem to be about $120-145 each. 3) Buy the cheapest tire and just replace them often. I see Milestar MS932 being very cheap ($75 shipped) for a long warranty, but not sure how long it would last or how loud it would be. Not racing this car so it should be good enough for handling and braking. 4) Mount the tires inside out mid way, but there are so many tires being asymmetrical I don't think it is worth the effort or risk if it gets into an accident and legal liability for mounting the wrong way. (I found a mom and pop that will do it without paperwork) Flipping cost about $20 each wheel. 5) buy those fuel efficient tires and call it a day, saving money elsewhere in fuel. Which route should I take? I don't care about Summer vs all season. Any V or above rated tire should be good enough.
 
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PandaBear

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Originally Posted By: Jarlaxle
Maybe get DIRECTIONAL tires, which could be "flipped" by switching them side to side?
I was thinking about that too, but it does get noisy not being able to rotate after a while. Also this car has different wear rate between left and right, so I'd prefer the ability to rotate instead of having to "flip" all the time.
 
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Unless your camber is zero, zero toe isn't ideal for tread wear. With negative camber, you need some toe out to have the tires run true, without fighting each other. Maybe there is some formula for the proper amount? Racing alignment books would be a good start.
 

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Originally Posted By: ddtmoto
Is the car lowered?
No, stock everything.
Originally Posted By: edwardh1
can u cut a slot in the adjustment bolt hole to allow adjustment?
There is no adjustment holes, the only way to adjust it from what I heard is to move the sub-frame a bit, go to the dealer to buy alternative bushing that let you adjust the toe / caster (forgot which one) about 20' (60' in a degree) at a time, or buy some alternative off centered poly urethane bushing that cost $300 or so each (with labor on both side probably a $1k job). That's a lot of tire flipping labor cost here.
Originally Posted By: IndyIan
Unless your camber is zero, zero toe isn't ideal for tread wear. With negative camber, you need some toe out to have the tires run true, without fighting each other. Maybe there is some formula for the proper amount? Racing alignment books would be a good start.
Surprisingly my speed shop guy told me 0 deg toe is within stock spec. What he told me is that the SAI (or Ackerman angle) is out of spec, but even for those IS that have perfect alignment, their tires still wear out like this.
 
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First, the IS250 has a TON of caster. That is certainly aggravating the situation. But you didn't tell us if the tires are wearing evenly or not - but since you are suggesting swapping the tires inside to outside, I think they are not. So unless you want to do some suspension work, I think you will continue to have issues. But you said this:
Originally Posted By: PandaBear
....... What he told me is that the SAI (or Ackerman angle) is out of spec......
You need to fix that! Out of spec Akerman can wear tires.
 
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Tell us more about the tire wear. *How* are the front tires wearing? Are they feathering the edges? Is there a sawtooth pattern across the width of the tire? How does it drive? Is turn-in crisp or is there some "play" in the steering wheel.
 

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There are no feathering, cupping, or any diagonal wear that is "unusual". Last year I was too busy and I forgot to rotate the tires for about 25k miles (1.5 year) and the left and right are slightly different in wear (1/32 vs 2/32 inner shoulder, and some of the typical front facing saw tooth pattern on the trend block / grove due to wear direction of not rotating). That's about it. Previous thread in 2010 Back then before I did the perfect zero toe alignment, I got a 1/32 inner shoulder, 4-5/32 center, 2/32 outer shoulder type of wear on both of the front tires (I rotate them often). I'm now getting around 1-2/32 inner shoulder, 4-5/32 center, 3-4/32 outer shoulder based on my eyeballing. So what I did is I ask a mom and pop tire shop to flip the inner / outer shoulder around (but it is an asymmetrical tire). That's the alignment that I found one side has an SAI / Ackerman that's slightly out of spec (forgot hot much, have to dig up paper work). Apparently SAI being off is common on the IS, and to do anything beyond the toe adjustment you need to move the subframe around. http://www.clublexus.com/forums/6482006-post15.html
 
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If you're getting that much shoulder wear on BOTH shoulders, relative to the center of the tread, I'd bump the inflation up some. Even after the alignment, both tire shoulders are wearing faster than the center is. I'm sure air pressure isn't the root cause here, but I think it's got to be a multiplying factor.
 

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If it is a gradual wear change across inner-center-outer trend, I think raising pressure will work, but it is a "sudden" drop wear on the shoulder like this. I don't think increasing pressure will help too much.
 

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Originally Posted By: Oldmoparguy1
That looks like the beginning of belt separation. I had one like that. Wayne
Agree, it is a blow out in the making. Not my photo, just borrowed from ClubLexus. Mine is much better than this and nothing down to the belt yet.
 
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