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Discussion Starter #1
First off, early last year i got a set of these for my grand prix gtp, 25k on them and about 30 passes down the 1/4, they still look new, i love them on that car.

So when the wife's G6 GT 3.5 needed tires i got her a set. We got a new set of tires because the damn handkooks it came with almost killed us in the rain a few times. Well at 15k they are done, both edges of all 4 tires are just gone, measuring about 2/32 to 1/32. Needless to say im a bit pissed at the wear.

The damn handkooks with 23k on them where wearing just fine. I actually sold them on craigslist with full disclosure of the rain issues.

I keep the tires at 35 psi, i have had the car put on the alignment rack twice now. The alignment is very good nothing to report. All the wheels are balenced and true, stock 17s, stock 225/50/r17s. We have had the car since 35k and its at 73k. No accidents.

Michelin gives these tires a 45k mile tread life warrenty. Michelin pretty much told me to kiss bricks on a warranty.

So my question is, since the car is straight and i know these tires car take way more abuse than a stock 3.5 what can i do to make sure this doesnt happen to the new set i have to buy? Why is a car that has no issues destroying a set of great tires?
 

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Generally speaking, treadwear and traction has a bit of an inverse relationship. Tires with great traction generally wear a little faster, and vice versa.
The treadwear rating stamped on the sidewall can give you an idea how different tires compare with each other. Maybe the Hankooks have a much higher rating than the Michelins that's why they last longer.
 

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I compared your Michelins to the Firestones that came on my car stock, I don't know which hankooks you had but I would assume it's similar to the crap tires mine came with from the factory.

The rating sounds good and so does the traction, the fact it's not wearing correctly is weird. I'd imagine even with a low wear rating you should see a longer life then you got.

When you got your alignment checked did you go to different shops? It's not likely but maybe the shop that did/checked your alignment has a machine that's a little off...

I was also thinking maybe the tires weren't mounted correctly. IE. Mounted backwards so the tire doesn't rotate the direction it's supposed to.

I have a set of Kumho Ecsta 4X. Those have an AA Traction but a 420 wear rating. It's been around 10k miles and I have no abnormal wear. Perfectly even throughout on all 4 tires.

I would go to the shop that installed them and start bitching, and continue bitching to Michelin. Claim you could have gotten seriously injured in an accident. Bitch enough and surely something should be done.
 

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Discussion Starter #5
They mounted fine, so is the alignment rack at the shop, like i said i have another set on my gtp that i abuse to all hell, no signs of wear at all. Let me try and get some side by side shots of the tires posted. Im expection 50k on my gtp with these tires.
 

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Discussion Starter #6
Ok the G6 set has 15k, the GTP, the gold car, has 25k on the tires, you tell me which ones look like the have mote miles on them.
Gtp on top

G6 right





G6 left
 

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Yea definitely too much wear on the edges. You mentioned in your first post that both edges of all tires are worn down. This honestly to me sounds like an under-inflation issue. When a tire has not enough air in it the center of the tread on the ground actually bubbles up, causing bad wear on just the edges of the tires. Maybe the rims or the Valve stems on the G6 had bad leaks.

If it was just on the inside or just on the outside of the tire then I would think it's a bad camber alignment. But with wear that consistent on all tires just leads me to under-inflation.
 

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Discussion Starter #8
Yeah thats what most think, but the car has the tpms, and i kerp them at 35 psi, i keep the ones on the gtp at 40 in the back and 32 in the front.

Camber readind from the alignment rack
LF -1.2. RF -0.6
LR -1.3. RR -1.0

I would understand if they burn up the inside edge, but both edges are gone.

Toe
LF 0.09. RF 0.08
LR 0.18. RR 0.10

Steer ahead
0.00
Thrust angle
0.04

All numbers well within the acceptable range
 

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I figured it had tpms and you kept the pressure up. And I would agree if you had wearing on the inside edge I would say alignment, but being on both edges is quite odd. The only other thing I can think of is poor tire quality. I really can't think of any other explanation.
 

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Discussion Starter #10
Yeah well thanks to living in cali those tires cost me close to a grand with all their bs fees. So im pretty pissed on the life i got out of them, yet my GTP is getting much better life, and hell i have rotated those once.

So i guess if I i get a different set of tires i shouldnt be worried about his again? Thats the main point of the tread, how do I make sure this doesnt happen to the next set. i was thinking of getting goodyear RSAs. I know they arent as good as these, but i simply dont have a grand lying around to gamble with.
 

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Well nothing significant changed between the hankooks and these tires. You simply got new tires and went on ahead. So It does sound to me like it's all within the tires. I would assume that a different set of tires would work without problem. But there is just no way of knowing. Tires are a lot of money and I can understand not wanting to continuously buy sets and sets of tires.

Do you know what the allowable specs are for alignments?
 

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Discussion Starter #12
Yeah i have a print out
G6 2008-2010 with hydraulic power assisted steering:
Camber in degrees
LF -0.3 to -1.5. RF 0.1 to -1.5
LR -0.2 to -1.4. RR -0.2 to -1.5

Toe in degrees
LF 0.00 to 0.20. RF 0.00 to 0.20
LR 0.00 to 0.20. RR 0.00 to 0.20

Steer ahead in degrees
-0.05 to 0.05

Thrust angle
-0.30 to 0.30

Caster in degrees
LF 2.2 to 3.7. RF 2.2 to 3.7
 

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Yea wow totally within spec. Next set of tires make sure you register and hold on to the warranty info, even go to they're preferred shop if need be.
 
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