duckvett

Just want to ask ALL C6 owners to check your front tire wear. I put our `10 Grand Sport up on a lift today to change oil & filter and found this.

Right front:



Left front:



These are Michelin Pilot Super Sport tires with approximately 28,000 miles. These tires were new on the car when we bought it at 12K miles. An alignment was done at 15K miles, Aug. 2013. A second alignment was done at 36K miles, May 2016. I personally inspected the tires during both alignment procedures and they showed NO unusual wear. Now at 40K miles they are worn to the cords.

Specs on the right front set during the 8/13 alignment:
Camber -1.4
Toe 0.02
Specs set on the right front during the 5/16 alignment:
Camber -1.5
Toe 0.10

Specs on left front set at 8/13 alignment:
Camber -1.3
Toe 0.08
Specs on left front set at 5/16 alignment:
Camber -1.4
Toe 0.02

All specs with the exception of the 0.02 toe are within GM specs. I originally asked the tech (independent alignment shop) to set Pfadt specs, but was told he "could not do that". You can bet that after I spend $1300-1500 on new Michelins, I will find a shop that CAN do that setting!

NOWUCME

Been there twice on vettes I have bought.

It's obvious from the wear and the alignment settings the Camber is killing your tires. Settings about twice what the Pfadt settings are for normal street. I know it's a problem to get someone to set them right.

I just put on a new set of tires and now have to find someone will come close to the Pfadt settings. Same thing happened to my C5, inside fronts gone. On my C6 now the back still have 6/32 and the front were pushing 2/32 just on the inside.

I wanted to get rid of the RF's anyway, so just need a good alignment now. Good luck to you on yours.

Also, I have heard said by some tire people that if the alignment is off the wear will be set at some point and you can't change with a new alignment. Don't know if that's right but could be, and maybe yours are a good example. But camber seems way over any high end range it should be. Maybe that last alignment really did them in.

50 ANV C5

new to the c6 forum im a c5'r but my gf just bought a 2011 gs and im curious whats ? Pfadt settings ? wheels aglingment settings ? thx

NOWUCME

Duckvette.....this might help. Pretty much the information in general I have found elsewhere before. Look at the difference your Camber set from what the post says, even on GM specs. Didn't look up GM specs. You probably have the Pfadt specs.
http://www.emeraldcoastcorvetteclub....tire_wear.aspx

50t Anv C5 - Yes, a whole set of alignment specs for different types of driving. Problem is the don't all agree with what GM wants and therefore what shops are willing to set for you........Google Pfadt and you will find it.

enventr

Lucky you checked. Wow, You got 40,000 miles on those tires while some cars get 20,000 miles. The tires lasted along time and if you had the correct alignment it would have lasted longer
I know I will probably buy these tires in the future

Don-Vette

That same thing happened to the Goodyear on my brand new GS at 7500 miles. Dealer said alignment was not within factory spec. So they set alignment and replaced all 4 tires free. No problems since and I'm on my 3rd set of tires, currently running Hankook Ventus evo2's.

Seadawg

Another tire to compare to the Michelin is the Bridgestone Potenza Pole Position in our Z06/GS sizes. I just checked my Discount Tire, and a set will run you about $1,200 installed, including road hazard, taxes, disposal, etc.

I've gotten over 30k out of two different sets, and that included drag strip, track days, and a lot of spirited driving. They were developed specifically for the Z06 and it's power level, which got me to try them in the first place.

They gripped almost as good when they were worn out as they did when new, and I've never heard any other brand to be able to do that.

I know my Michelins and Goodyears would not grip well at the end of tread life.

Anyway, just something to consider

Seadawg

And here is the link to their recommended settings.

http://www.pfadtracing.com/blog/wp-c...-alignment.pdf

AORoads

Just a small correction: OP said in first sentence, 28,000 miles on these tires; bought car w. 12K miles on odometer.

OP, that is very good advice to check tires! I had found a very good alignment person(county corvette, CF vendor) from day one of a different model of Michelins and at 24K miles, they looked very evenly worn across the face. Like you, I don't treat an alignment as a once-when-I-buy-the-tires thing------not at $1200-$1800 per set!!!!

duckvett

Thanks for that link - the specs shown vary just slightly from another Pfadt chart that I printed several years ago.

ruxvette

Which Bstones...RE17, RE11, or runflat RE 050?

ProCycle

There's always the DIY approach:

https://dl.dropboxusercontent.com/u/1634366/align.pdf

I've used David Farmer's method on my C3 with good results and I have the necessary tools to do this.
If you want to take a whack at doing your own bring it on over

If you don't want to dive in yourself we can always check the results after you have it done.

Not So Fast

40,000 miles, wow impressed.
I just bought my self a tread gauge so I will be checking my new Hankook tires regularly. The Nittos we took off were worn pretty evenly with a slight inward wear.
NSF

cclive

The OP has too much negative camber. This is what is causing this wear. My original GYs had the same inside edge wear at 20,000. My negative camber is now -0.3 and all is good.

enventr

Thanks for the correction as I was not paying attention

INTRCUL

-1.4 is very aggressive for a street car and already past PFADT's recommendation for a street tired car. I'm surprised you even broke 20k miles with that setting. It doesn't look like you tracked the car so going back to the factory GM spec of maybe -0.5 would probably get you nice even wear and at least 30k mileage out of the next set. Anything less than that and you'll wear out the outer edge of the front left from on/off ramps, exact opposite problem you have now.

Also, the Michelin SS is a dual compound tire with the softer compound on the outer ribs. This is how they get high lateral grip with the crazy 300 treadwear. Most of the time the car is riding on the middle/inner ribs but when turning the stickier outer ribs come into play. The less camber run could accelerate wear since that compound will be touching even in a straight line and you could end up with less than 15k for the outer ribs and almost new looking inner ribs. The SS is the best performing tire around right now and can still get great wear with proper camber settings.

dmk0210

So for street use PFADT recommends -0.7 to -0.9 front camber / -0.4 to -0.6 rear.

What is the GM spec range for camber?

If they won't do custom settings, I would damn sure argue to at least get the minimum camber spec'd by GM.

Duckvette, you should go back to that shop and show them what their alignment did.


.

trying2seek

I need to move to Florida I just paid 1800 bucks for the Potenza Pole Position RFT in Colorado and used a employee discount..

cclive

If they won't do whatever specs he wants, he should go somewhere else.

Eritosthenes

I agree. The factory camber spec of -0.45 degrees plus/minus 0.6 degrees has always resulted in premature inside corner front tire wear. You will get much better and even tire wear by setting it as close to -0.10 degrees as possible. This is close to perfectly vertical and will cause the tire to wear evenly across its entire footprint. The less aggressive spec will not affect street handling at all.