Tire wear

[sd1209]

My wife bought a new 2022 Stinger GT1 a couple years ago...Has the original Michelin Pilot Sport 19" tires......It has 15K miles and she recently took it in to the dealer for an oil change....The service advisor told her the rears were wearing unevenly and would need to be replaced shortly.....He also said that getting 20k out of a set of 4 tires is good for the Stinger......I looked at the rears and they are wearing unevenly but not bad......

Question: wife is 70 and drives like 70...Very easy on the car....Was the service advisor correct in getting 20k out of a set of tires easily driven is about it?? Or was it a sales pitch for new tires?? Just never heard of that kind of normal wear, maybe in the 1960's but not today......I have not read the book yet, can the rear be aligned???

 

[bfglitch]

From everything I've been seeing, it seems the factory alignment on the car tends to have a bit of negative camber which wears the inner edge of the tires. Also if they're staggered, rear wider than the front, (which I'm guessing they are), you can't fully rotate the tires. This usually causes the rears to wear faster than the fronts since the car is RWD biased (or fully RWD if you don't have AWD).

Most of the folks on here have reported appx 15-20k average on the Michelin PS4's.

 

[7Andrei7]

My rears wear more in the center than the sides. I take very good care to monitor my tire pressure and keep them at required 36 psi (cold).
But, you can change the rears alone and get another 15-20k miles from them before the fronts are done. At least on the RWD.

 

[Snicklefritz]

awd here. I go through two sets of rears to one set of fronts, more or less. I get around 15,000 miles out of a rear set. michelin's 30,000 treadlife warranty is halved in the rear on staggered setup. but some on the forum get over 20,000 out of their rear tires. sounds like your wife ought to as well, but it's likely that she's a secret, occasional lead foot because it's fun at any age. inside edge wear is because the factory spec tends to cause that, as already mentioned. mine certainly do wear on the inside edge first. I've been advised to instruct the alignment folks to adjust the factory spec by a degree more positive camber next time, based on the amount of outer edge tread I had left.

 

[Ozstung]

4 sets of tyres since new (almost 6 years old) i get twice as many km from the fronts. These cars eat rears I'm 60 and i got only 15k km! Out of rear potenzas. My record was the initial conti 5s at 28k km for rears.

 

[killinghall]

I'm easy on the car as well and have done 24,000km. Looking at current tread depth, it should last me till 30-35,000km. So 20,000 miles thereabouts.

 

[Silverghost]

... I've been advised to instruct the alignment folks to adjust the factory spec by a degree more positive camber next time, based on the amount of outer edge tread I had left.

Hi fritz, have you had the alignment adjusted with that extra positive degree? Any update on wear or too early? I have just had my 20" summer Nitto 555 replaced with 18" winter rims and the Nitto rear inners were beginning to show the steel belts after 35,000 km after 4 years. Thinking of doing that same extra +1 degree alignment change.
I appreciate any feedback.
Thx

 

[Kazz]

In general, tirewear is affected by inflation, alignment, and driving style.

Given a 'neutral' alignment (0 degrees of camber) that keeps the wheel and tire a perpendicular 90 degrees on the pavement, outer tire wear means the tire has been run underinflated. Tire wear in the center of the tire means the tire has been run overinflated.

Camber affects the angle. Negative camber moves the top of the wheel inward towards the vehicle. This creates more wear on the inside edge of the tire. Positive camber moves the top outward, away from the vehicle, creating more wear on the outside edge of the tire.

An aggressive driving style that hits corners hard will create tire wear towards the outside of the tires. This is why racers and more aggressive drivers use negative camber. The goal being to make the wear even across the width of the tread of the tire.

When the inside or outside of a tire is wearing more than the rest and the above has already been taking into account, the most likely culprit is toe adjustment. This is done during an alignment. Toe is the angle of the wheel front-to-back. If the front of the wheel is angled outwards (toe out) the inside of the tire will wear. Angled inwards (toe in) the wear occurs on the outside of the tire. Improper toe also often creates a 'cupping' effect across the tread over time. This creates audible tire noise in the cabin. If you rotate your tires and hear noise from the rear, for instance, the toe is likely off front, rear, or a bit of both.

Remember alignment settings are corner-specific not axle-specific. This means a single wheel/tire can be out of alignment and wear improperly.

Generally, keep all alignment settings within factory range limits (alignment technicians have access to this info), especially toe. That is what most often ruins tires over time.

Sorry this is so long. Hope this helps someone!

 

[Silverghost]

In general, tirewear is affected by inflation, alignment, and driving style.

Given a 'neutral' alignment (0 degrees of camber) that keeps the wheel and tire a perpendicular 90 degrees on the pavement, outer tire wear means the tire has been run underinflated. Tire wear in the center of the tire means the tire has been run overinflated.

Camber affects the angle. Negative camber moves the top of the wheel inward towards the vehicle. This creates more wear on the inside edge of the tire. Positive camber moves the top outward, away from the vehicle, creating more wear on the outside edge of the tire.

An aggressive driving style that hits corners hard will create tire wear towards the outside of the tires. This is why racers and more aggressive drivers use negative camber. The goal being to make the wear even across the width of the tread of the tire.

When the inside or outside of a tire is wearing more than the rest and the above has already been taking into account, the most likely culprit is toe adjustment. This is done during an alignment. Toe is the angle of the wheel front-to-back. If the front of the wheel is angled outwards (toe out) the inside of the tire will wear. Angled inwards (toe in) the wear occurs on the outside of the tire. Improper toe also often creates a 'cupping' effect across the tread over time. This creates audible tire noise in the cabin. If you rotate your tires and hear noise from the rear, for instance, the toe is likely off front, rear, or a bit of both.

Remember alignment settings are corner-specific not axle-specific. This means a single wheel/tire can be out of alignment and wear improperly.

Generally, keep all alignment settings within factory range limits (alignment technicians have access to this info), especially toe. That is what most oftenwinter ruins tires over time.

Sorry this is so long. Hope this helps someone!

Thx Kazz for the detailed insights. I have all "winter" to get new summer tires. Appreciate the information.

 

[Snicklefritz]

Hi fritz, have you had the alignment adjusted with that extra positive degree? Any update on wear or too early? I have just had my 20" summer Nitto 555 replaced with 18" winter rims and the Nitto rear inners were beginning to show the steel belts after 35,000 km after 4 years. Thinking of doing that same extra +1 degree alignment change.
I appreciate any feedback.
Thx

I haven't had an alignment in over a year, and that one was the first in ownership of well over five years. I know, just because everything tracks straight doesn't mean the alignment isn't off. so, the inside edge wear in the rear was almost entirely caused before the alignment, probably by negative camber and not driving 'aggressively' enough. hopefully, I have corrected both issues since then. ha hah.

my current rear ps4s have less than 4,000 miles on them, in just under half a year, and appear to be wearing unevenly. looking these pictures over, it looks like I am wearing on the inside still, perhaps heavily so. I will make an alignment appointment this week and get back to you. I'll show them the wear missing the outside tread and ask them to adjust accordingly.

 

[Snicklefritz]

just returned from an alignment. Very small adjustment, from negative 1.4 to 1.2. The Stinger spec is between .7 and 1.7, or maybe 1.9, Ima uncertain which I heard. it was funny. the tech said, 'you have very soft tires.' and I of course concurred, that michelin are the stickiest road tires out there with a low treadlife warranty, cut in half besides. he said he was mentioning it out of sympathy. after I explained how Ima not that concerned about getting around 15,000 miles out of my rear tires, I just would prefer to not have them wear unevenly, he said, 'I need to rethink this.' he told me a couple of times to just have fun, since the setup of the stinger is designed to advantage stability as speed increases. this I already knew. he explained that if you moved to the low end of spec camber, .7, it would negatively affect handling at higher speeds especially. and I said I don't want that, I'll take faster inner edge wear, thank you. over time, I'll be able to see if .2 less negative camber affects wear across the tread. it could, over the life of the tire.

 

[Volfy]

Your tire wear look fine to me. In normal street driving, your camber angle would need to be well outside the spec'ed range, for it to affect tire wear significantly. Toe angles that are off could potentially have a lot more effect on inside/outside uneven wear. That is because when there is excessive toe-in or toe-out, your tires will have a slight slip angle even when going dead straight. The slip angle will exert a constant force on the tire, causing friction/heat/wear. For road cars, a tiny bit of toe-in (less than 1deg total) for the rear axle is acceptable - even desirable for straight-line stability. For the front, spec typically call for zero toe (straight ahead) for road cars. Race chassis sometimes benefit from some toe-out, to quicken turn-in, at the expense of straight line stability. The trade-off is worth it, if faster cornering gives you an advantage on tighter, more technical, courses.

Also, for high speed handling, the car's spring rates and damping have a lot more effect than your camber (again, as long as the angles are within spec range). Where camber angle matters a lot more is in cornering, particularly at or near the limits. In normal driving, you'd be hard pressed to notice the difference of a few 10/ths degree difference.

 

[Snicklefritz]

^^thanks. the toe was already spot on. all they could do was take out a couple tenths of a degree of camber. and we'll see if the tread wear by the end of the life of the tire is more even than the last pair, which were showing belts on the inner edge while the outer edge still had tread above the wear bars.