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For those here with longer Cayman/Boxter experience, how would you characterize tire wear mileage?

For instance, would you say the front tires last about twice as long as the rears? If so, then when the original rears wear out and are replaced, the fronts still have a lot of wear remaining. So you replace those worn rears with the same brand/model tire and go until all four are worn out about the same time?

My 2017 Cayman S has about 12k miles on it, and the dealer is suggesting I should consider changing the rear tires "soon". But the fronts have more tread left; hard to say just how much mileage that translates to. These are 20" Goodyears. I would like to change to Michelin 4S all-round but I'm reluctant to "waste" remaining mileage on the front Goodyears!

Thinking back, I recall a similar situation years ago with my 91 Toyota MR2. Rear tires were shot at 19k and replaced. I "flipped" all four tires on their rims inside-to-outside at 28k to extend the wear, as they were wearing more on the inside. When I traded the car in at 40k all four needed replacement. So on that mid-engine car the fronts lasted roughly twice the mileage of the rears.
 

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Can't you measure the remaining tread yourself with a tire tread depth gauge? Look up the amount of tread your tires had when new. Probably 10/32 inch. Calculate what % you used up in 12K miles & extrapolate to when they will need replacement. 2/32 is the legal limit, I believe & some people replace as early as 4/32. I think you get a lot of rain so you may want to replace @ 4/32.

If you need to replace the rears, why can't you use Michelins & then later get Michelins for your fronts?

I wonder if it really is bad for performance cars or just a common theme echoed by all sellers of tires in order to convince drivers to trash perfectly good ½ worn tires in order to match.

I do think it is a big mistake to mix tires on the same axel but I am not so sure about one brand on the front axel & a different brand on the rear axel. I'm certain some people have done this.
https://rennlist.com/forums/993-forum/103509-tire-experience.html

I'm also pretty sure people who advocate NOT matching Front & Rear exactly will get flamed ;)

Obviously they should be very similar, speed rating, NO, Summer with summer, performance with performance, etc.
 

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I have not received my 718 yet (2019 build) but can comment on having owned 4 Caymans (08 CS, R, 2014 and current 2016). My rears always wore out much faster than the fronts. I typically have replaced the fronts with every second set of rear replacement. I check my tire pressure at least weekly, do 4 wheel alignments at every tire replacement. I have always had very even tire wear. I have had Michelins, GoodYears, Pirellis and they have all exhibited similar pattern. I achieved the best tire wear (Mileage) from the GoodYears and worst from the Pirellis. The soonest I have had to replace the rears is at 16,000 miles. I ran a few track laps at Sebring with the 2014 (GoodYears) and 2016 (Pirellis).
 

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RGM718,

Did you always replace the rears with the same exact tire that had worn out so it exactly matched the fronts?

If you changed tire brands, did you wait until you wore out the 2nd set of rears so that the fronts were also worn out & you could replace all 4 & change brands w/o mixing?

I don't like that idea, unless you are happy with the original tires.

If you are not happy & want to try a different brand, it seems so wrong to just buy another new pair of the same kind for the rear just so they match.
 

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For those here with longer Cayman/Boxter experience, how would you characterize tire wear mileage?

For instance, would you say the front tires last about twice as long as the rears? If so, then when the original rears wear out and are replaced, the fronts still have a lot of wear remaining. So you replace those worn rears with the same brand/model tire and go until all four are worn out about the same time?

My 2017 Cayman S has about 12k miles on it, and the dealer is suggesting I should consider changing the rear tires "soon". But the fronts have more tread left; hard to say just how much mileage that translates to. These are 20" Goodyears. I would like to change to Michelin 4S all-round but I'm reluctant to "waste" remaining mileage on the front Goodyears!

Thinking back, I recall a similar situation years ago with my 91 Toyota MR2. Rear tires were shot at 19k and replaced. I "flipped" all four tires on their rims inside-to-outside at 28k to extend the wear, as they were wearing more on the inside. When I traded the car in at 40k all four needed replacement. So on that mid-engine car the fronts lasted roughly twice the mileage of the rears.
Everything you describe is typical of a mid-engine RWD car, a fact borne out by your previous experience with the MR2.

You can partially mitigate the uneven wear between rear and front by running the fronts at a lower PSI, which is what I have done with my stock Yoko Advans primarily to wear them as quickly as possible. (I've been running 29F-31R). I'm replacing those next week at 7,800 miles with Conti EC Sports, which I will run at 32F-35R to start. The Yokos are at 2/32 in the rear and (barely) 4/32 in the fronts.

(FYI: I passed on the PS4S in favor of the Contis because I scored the Contis for significantly less, and they supposedly have better wet traction than PSSs and, by some accounts, the PS4Ss).

I can't emphasize and recommend strongly enough that you should replace all four tires at this stage. NEVER run different sets on a performance car, especially one with staggered wheel widths -- and never run performance tires at significantly different stages of wear. You can get away with that with all-season tires designed for mileage and abuse, but you can't get away with it in high-performance tires on which heat cycles, layered rubber compounds, etc. create huge differences in per-tire performance.
 

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When I traded my CS in the dealership stated my rear tires look "tired" after 7300 miles of I must say spirited driving; of which the first 2K break-in miles were sedate. I know that Porsche tires are an expense but I will factor in for the sheer joy of driving.......worth every penny.
 

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I always replaced the rears to match the fronts (N series might have differed by 1 e.g., N0 replaced with N1----this was only in the event that there were no more of the N0 available.....only happened once). If I wanted to switch brands (I never did by the way) I would have switched all at the same time, I would not have mix brands. That is just me.
 

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I'll add that the extreme version of this accelerated rear tire-wear tendency in mid-engine cars is the 1st-gen Acura NSX. It ate through rears at the clip of 4k miles per set. Average. Some barely lasted 3k. Why? Staggered widths AND diameters, aggressive stock alignment, and unusually low unsprung weight as OEM, in addition to the mid-engine-RWD layout.

It was such a big issue for Honda that it provided a tire stipend for many customers that lasted through the NSX's warranty period.
 

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Discussion Starter · #9 · (Edited)
Thanks... I wasn't sure if this was typical mid-engine behavior, as on the MR2 I understood that normal movements of the rear suspension caused a good bit of geometry change, accelerating wear I suppose. At 19k one of the rear original Bridgestones turned out to have steel cords peeking through on the inside edge where it was hard to see.

At Porsche service a couple of weeks ago, the report indicated the tread depth was 4/32 rear and 6/32 front.

Thinking of Michelins for the CS, I'd be after lower road noise and an increase in comfort. This is not a daily driver, nor found on the track... most mileage is on trips on lesser highways at vigorous speeds. This Spring we were in Flagstaff a couple weeks, returning through Las Vegas, Tonopah, Lee Vining, Sonora Pass, Angels Camp, Tahoe, Truckee, Sierraville, then onto 395 through Lakeview to Pendleton. What a ride! :) We're on the dry side of a wet state, but we get ice. I try to stay off the ice, but did get caught out in December several hours from home when it turned icy, and the Goodyears were amazing that time. Silica added to the rubber is good for that.

Doug
 

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There have been some studies that indicate that evenly worn tyres may have better performance on dry roads than new ones, not in the wet though.

I wasn't interested enough to follow it up but a Google search should get you going.
 

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I am guessing that the dry road better performance of evenly worn tires is largely due to the reduced tread depth and less tread to move around under hard cornering......the extreme of this, of course, is why race cars run slick tires in dry conditions.
 

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At what tread depth do you replace your tires?

This thread hasn't really discussed tread depth, hope it's ok I bring it back to life with my question.

The tread depth on the rear tires of my Boxster have reached the yellow band on my super duper tread depth measuring device. I was curious at what point you are looking to replace your tires. Are you one to wait until you're in the red or do you start getting a little anxious driving on wet roads when they start showing some wear?

I've got 11K miles on the car. Wear is pretty even across the face of the tires. I've autocrossed the car twice. Plan to change all 4 at the same time to a different tire manufacturer. Even though the Yokohamas have a tread wear of 240, they didn't feel very grippy while autocrossing.
 

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This thread hasn't really discussed tread depth, hope it's ok I bring it back to life with my question.

The tread depth on the rear tires of my Boxster have reached the yellow band on my super duper tread depth measuring device. I was curious at what point you are looking to replace your tires. Are you one to wait until you're in the red or do you start getting a little anxious driving on wet roads when they start showing some wear?

I've got 11K miles on the car. Wear is pretty even across the face of the tires. I've autocrossed the car twice. Plan to change all 4 at the same time to a different tire manufacturer. Even though the Yokohamas have a tread wear of 240, they didn't feel very grippy while autocrossing.
I replaced my OEM Yoko Advans just short of 8k miles; I measured 3/32 on the wear indicator for the rears the day before. The fronts were between 4/32 and 5/32. I'm not sure what your gauge is reading regarding the colors (yellow and red = what tread depth?), so I can't give you specific advice ... but you did get much more mileage out of your Advans than I did, so there's that ...

Conventional wisdom varies, but it's not advisable to run tires below 4/32 tread depth on public roads. At 5/32, wet-weather performance begins to deteriorate substantially, particularly regarding hydroplaning and liquid dispersion. Also, as noted previously, rubber performance changes with time, wear, heat cycles, etc. -- particularly on a (relatively) soft-compound three-season tire. I noticed that my Advans lost dry traction noticeably at about 5,500 miles.
 
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I'll look to change my tires when they get to the wear indicators on the tires.


I have the Yokohama advans. The rears seem to wear twice as fast as the fronts. So I've already replaced the rears, and the fronts are still fine. When the fronts wear out, which will probably also be when this set of rears wear out I'll swap all four out for Michelin Pilot Sport 4S tires.
 

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I'll look to change my tires when they get to the wear indicators on the tires.


I have the Yokohama advans. The rears seem to wear twice as fast as the fronts. So I've already replaced the rears, and the fronts are still fine. When the fronts wear out, which will probably also be when this set of rears wear out I'll swap all four out for Michelin Pilot Sport 4S tires.
How many miles did you get out of the rear tires?
 

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I'm driving a Cayman in New Zealand and our specification has the car arriving new wearing Pirelli. I changed these after 15k kms (10k miles) which i thought was pretty poor. I replaced them with Michelin PSP4 and they are excellent. Seem to be better wearing but i would definitely say they are noisier on the harder road surfaces. The grip is fantastic. It's winter here and plenty of frost in the early morning but no slip at all.
 

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You shouldn't be penny-wise and safety foolish. What's your well-being worth to you?

Buying and driving a fairly expensive car is more than just the initial cost of ownership. It also comes with the addition expense of running it properly. One must be responsible for themselves and those that ride with them. Trying to save a few dollars can end up being dangerous. So, factoring in the running cost and maintenance must be taken into account.

I'd replace both fronts and rears at the same time. Not only will the car drive better,it will be safer.
 

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rear tire wear

have a 2017 boxster and have had to change rear tires every 5000 miles. They are so bald they don't pass inspection. This is my wives car and it is garaged and she drives it very gently. They have inspected it and the alignment is good. There are no signs of abusive driving according to Porsche. Yet Porsche says the only thing it could be is my 55-year-old wife lighting the tires up and apparently crawling underneath and scrubbing the wheel wells clean each night. we have worn 2 pairs of tires with only 10,000 in 2 years. Love the car but these people are Thieves!
 
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