boofus1

What sort of mileage are people getting on their OEM Grand Sport tires?

lavla

There are varying opinions on this one. I spoke with a Michelin rep at Carlisle and was told that I could expect around 15k miles on my 2017 GS tires. While speaking with others (?), I was told to expect around 7,500. I'll be happy if I can get 15k. I don't race the car or drive aggressively but do drive to Florida and back to NJ each winter. As more time goes by, I'm sure we'll hear from people with actual experience.

boofus1

Thank you. What strikes me as odd is that the tire is warranted for 30K on the front, 15K on the rear. Why would Michelin say to expect only 15K?

lavla

I called Michelin and had them send me the pamphlet outlining the their warranty(ies). They DO have a 30k warranty on their tires but it does not extend to their Summer Only Performance tires.

aj98

Wonder if their average life calculation incorporates a lot of wheel spinning

dbaker

With a good alignment..maybe.

Mine was off and had it corrected.Worth it.

\db2

mountainears

And remember, there are two different tires available on the GS. If you have the Z07 package you have the Cup 2 tires. Much shorter tire life expectancy on the Cup 2 tires.

I live in the foothills, lots of windy roads that are fun to drive. With that type of tire scrubbing I'll be happy with 15k I think.

Ramler

I was told by Discount Tire that all manufacturers cut the mileage guarantee in half on the drive axles if tires cannot be rotated. Sort of makes sense.

BELVIN20

I do not have a Grans Sport, but have a Z with the Super Sports, I have a little over 15k on the tires, they are down to wear bars in front, & maybe 3K more on rears, car was aligned right after I got car, tires wear was flat all the way across the tires. Alignment is the key to get max tire life on the SS. Possible if you drive real easy, you can get 20k miles on them.

JerryU

I had my tires aligned at 400 miles. The GM spec for the Grand Sport is very wide. They came with cambers ranging from -1.4 to -1.7. That is the top of the range, good for tracking.

Had them aligned to the low end of the spec, -0.6 to -0.8. That will give more uniform wear. As outlined in the Owner's Manual, I'll rotate side to side at ~5000 miles.

iclick

My GS has 4k on the clock and I log tread depth regularly. Based on 2/32" replacement I calculate that at the current wear rate I should get 43k out of both front and rear, but I'm not expecting it. I would be happy with 30k, but perhaps these tires wear faster as the miles accumulate. Since they're all wearing well and consistently I haven't had the impetus to have my alignment checked, which I usually do by this time after buying a new car.

Note that there are three large grooves, and the inside groove of GS/Z06 tires, both standard and Z07, have less tread depth. Mine had 7.2/32" outer and mid, and 6.7/32" inner. I double-checked this on some new cars at a dealership and found the same. I always check using the outside groove, that is until I rotate them, at which time it will be the inside groove.

TEXHAWK0

I have over 13,000 miles on my pilot sports, with about 5/32" tread left on the fronts. Wearing evenly across all tires.

NASTYC7

Wow you sure do get into your tire details... Me.. it's more like "Damn a new set needed already"....

JerryU

Hmm, can't rotate the C7 tires so the INSIDE groove becomes the OUTSIDE groove! The tires are not "directional," they can be on either side of the car and as the Owner's Manual states, rotated side to side. BUT they are "asymmetrical!" They can ONLY be mounted with the side labeled OUTSIDE facing outside. If you have a flat fixed, when remounted the word OUTSIDE must be placed on the outside of the rim, right where it was!

DETAILS:
Have seen a number of posts where some folks say I won't rotate tires because I don't want to have to dismount and remount the tires! That is wrong. The tires have different construction (and perhaps tread compound) inside and out. Just like the outside tread width is wider than the inside, so is the inside belt construction different from the outside.

Why? When achieving max holding force on a curve the outside of the tire on the outside of the turn has the most load. The inside tire is more lightly loaded so it is not as critical. On some stiffly sprung race cars you can actually see the front inside tire lift off the pavement on a high "g" turn! It is contributing nothing to the cornering force. The outside of the tire on the outside of the turn, whatever side of the car it's on, is where the most grip is required when making a high speed turn.

PS: You can see the word OUTSIDE on the tire. There is so much writing on the tire you have to look carefully but the word, in all caps, is on the outer line of text!

Note: Fun to think about!
1) There are tires that are directional and not asymmetrical. They cannot rotate in either direction and MUST be dismounted and reversed when rotating side to side. They usually have a rotation arrow on both sides.
2) There are tires that are directional and asymmetrical. They cannot be rotated left to right only front to back (if they are the same size.) Those tires are labeled right or left or OUTSIDE with a rotation arrow the outside writing!

bjones7131

So can my 17 GS tires be rotated side to side, if I am reading your info correctly they can be, correct.

JerryU

Yep, page 276 of the PDF version or the 2017 Owner's Manual:

Tire Rotation: The tires should be rotated every 7,500mi. Tires are rotated to achieve uniform wear for all tires. The first rotation is the most important. Anytime unusual wear is noticed, rotate the tires as soon as possible, check for proper tire inflation pressure, and check for damaged tires or wheels. If the unusual wear continues after the rotation, check the wheel alignment. Use this rotation pattern if the vehicle has different size tires on the front and rear. (Pic shows side to side.)

Note, no remounting. I'll jack up both sides and swap at ~5000 miles and swap side to side.

rikhek

If driven in a sporty manner you should be happy getting 5,000 miles from a set.

papillion

If you're concerned about the cost of tires, you are considering the wrong car. No matter, when they look thin on tread you replace them. Oh and my neighbor got 50K on his Prius OEMs.

JerryU

Sorry misread your post and responded incorrectly.

Not my first error. However what I posted may help some who said they won't rotate as they don't want to have the tires remounted.

See you're talking about where you measure! Mine is simple. Have a favorite, not widely used 270 degree exit ramp. Grass field on the left. The driver's front tire gets the highest use so the outer tread is my indicator as when to rotate if it should be sooner than ~5000 miles.

iclick

I'm OCD on details of all kinds, the C7 tires being only one. It's an incurable disease and almost a fetish. I watch tire wear on a new car closely because I always assume the factory alignment isn't very precise. With the wear I'm apparently getting I doubt if alignment could be improved for tire wear..