[Docb]

718 CS 2017
Finally here great car every day driver. 15k mi no issues. Did downsize to 19" from 20". P zeros bubbled twice. Switched to Michelin PS4s on. 19" HREs. 2017 Porsche Cayman HRE Wheels 540C
Satin Black centers
Polished clear coated lips Satin Black Barrels 19x8.5 front 19x10.5 rear Michelin Pilot Sport 4S 235-40-19 285-35-19 pressure valves Mounting and road force balancing.
No problems tons of traction.

 

[jimmuller]

Why the downsize from 20" to 19"?

I have 20" because that was what was on the car. I can't say I know the pros and cons of 20" vs. 19" other than the probability of scraping a curb when parking. I've never owned a car with 35 series tires before. The car corners with such precision but I couldn't say whether it is the tires or the car itself. I like to think it is both.

 

[BB718]

the 20" combo looks best on the Boxster

 

[antennahead]

Why the downsize from 20" to 19"?

While the 20's look better, in my subjective opinion , the roads here where I live, on the coast, just have too much settling and potholes for a 35 series sidewall. The 19's are far more comfortable and still look good. These comments are geared towards street use only, YMMV

 

[GTS]

I'm in the, " I'd like to downsize to 19" wheels" camp too. I haven't done it yet, but feel like it's a good choice on crappy urban and rural roads. The roads in my suburb are fine for the 20's, but I worry too much when I go on longer drives in unknown territory.

 

[jimmuller]

So the wheel damage susceptibity is the biggest problem. We have some bad roads too but I figure it's my job as driver to be careful.

 

[JakiChan]

I went with 19s for this very reason. I don't love the 19" options for the CS, but I don't hate them either.

 

[Naptown]

No issues with my 20"wheels.

 

[duegatti]

My 20 inchers have been through some terrible pavement at highway speeds; no problems. But I have an third party tire/wheel warranty. Looking at them, I can't believe they can hold the car up standing still, let alone out on the road, but they do. I also have PASM and find the ride to be fine.

 

[DriveInHouston]

I have 20" rims with Michelin PS4S. I've had problems with hydroplaning during some deluges we 've been through this year. It happens either if the asphalt on the freeway has developed tire 'grooves' (more like shallow ditches) due to traffic, and water is deeper there, or at the seam between to lanes (again, it is a water collection area, if the lanes are uneven). The tail suddenly shakes and I have to correct it (sometimes it is out over a foot), it is rather scary as it happens on a straight line.

I am thinking about changing to All Season tires because they have lateral sipes to remove the water from under the tire. The Summer Extreme Performance tires like the PS4S do not have lateral sipes (any brand) and I am willing to trade-off maximum performance for more balanced performance in the wet (and the cold).

I haven't found rear ones for the 20" rims, unless I put a non-standard dimension. So I am looking into 18" or 19" rim/tire combinations

 

[roundtail]

Why the downsize from 20" to 19"?

I have 20" because that was what was on the car. I can't say I know the pros and cons of 20" vs. 19" other than the probability of scraping a curb when parking. I've never owned a car with 35 series tires before. The car corners with such precision but I couldn't say whether it is the tires or the car itself. I like to think it is both.

It is both, although tire design has a profound effect on just about any vehicle. That’s why Porsche has proprietary specs with the manufacturers.

 

[roundtail]

I have 20" rims with Michelin PS4S. I've had problems with hydroplaning during some deluges we 've been through this year. It happens either if the asphalt on the freeway has developed tire 'grooves' (more like shallow ditches) due to traffic, and water is deeper there, or at the seam between to lanes (again, it is a water collection area, if the lanes are uneven). The tail suddenly shakes and I have to correct it (sometimes it is out over a foot), it is rather scary as it happens on a straight line.

I am thinking about changing to All Season tires because they have lateral sipes to remove the water from under the tire. The Summer Extreme Performance tires like the PS4S do not have lateral sipes (any brand) and I am willing to trade-off maximum performance for more balanced performance in the wet (and the cold).

I haven't found rear ones for the 20" rims, unless I put a non-standard dimension. So I am looking into 18" or 19" rim/tire combinations

Hmm. I would do some serious research before taking that plunge. All season tires won’t have near the dry traction as your current tires and may not do nearly as much to dampen your hydroplaning issue (sorry for the bad puns ) as you’d like. Even on 18” rims dropping to 9.5” at the rear, these tires have a wide footprint, making them more prone.

I drove through a torrent several weeks ago on the stock Pirellis and had no problem with the speed dialed back...as hard as that is to do in a Cayman.

(edit) My daily driver is a Tacoma 4x4 with “all season” tires, and it’ll hydroplane on me in a blink in deep-water road ruts.

 

[DriveInHouston]

Hmm. I would do some serious research before taking that plunge. All season tires won’t have near the dry traction as your current tires and may not do nearly as much to dampen your hydroplaning issue (sorry for the bad puns ) as you’d like. Even on 18” rims dropping to 9.5” at the rear, these tires have a wide footprint, making them more prone.

I drove through a torrent several weeks ago on the stock Pirellis and had no problem with the speed dialed back...as hard as that is to do in a Cayman.

(edit) My daily driver is a Tacoma 4x4 with “all season” tires, and it’ll hydroplane on me in a blink in deep-water road ruts.

Thank you for your reply, that is the reason I posted, to hear other people's opinions.

My Michelins have 7k mi. on them, plenty of tread left. I experienced hydroplaning doing 55-65 mph, and felt dodgy even at 45-50 mph. Lots of water though, I could barely see where I was going...

 

[jimmuller]

I experienced hydroplaning doing 55-65 mph, and felt dodgy even at 45-50 mph. Lots of water though, I could barely see where I was going...

One of the first days I drove mine to work I went through a similar downpour on the way home. I slowed out of fear, bur never had a problem. Tire are P4S, 20" wheels. Even our Caravan has had a rare hydroplane event. So I wouldn't blame the tires, nor would I think all-season tires will prevent it. Put enough water on the wrong shape road and you can have a problem anyway.

 

[roundtail]

Thank you for your reply, that is the reason I posted, to hear other people's opinions.

My Michelins have 7k mi. on them, plenty of tread left. I experienced hydroplaning doing 55-65 mph, and felt dodgy even at 45-50 mph. Lots of water though, I could barely see where I was going...

I can’t speak to the Michelins as I have P-Zeros on 19” wheels, so a different animal. However, I have an early 2018 build and it came with N1s on it. The Boxster we just bought had new P-Zeros installed shortly before trade-in, and those are N2s.

Why I bring that up is they have different siping patterns that run further across the tread than my N1s do. Just by appearance, it looks like the change would be to improve wet performance. So perhaps there may be a better wet-spec version of tire for yours as well.

Just keep in mind every tire is built against competing objectives: dry vs wet, ride vs wear, etc. The trick is to find the right balance for the bulk of your needs/wants.

 

[jimmuller]

It is both, although tire design has a profound effect on just about any vehicle. That’s why Porsche has proprietary specs with the manufacturers.

Well, of course tires and car are designed to work together on a car like these. I didn't quire say what I was thinkin'. I was wondering if smaller wheels would feel much diffetent.

 

[roundtail]

Well, of course tires and car are designed to work together on a car like these. I didn't quire say what I was thinkin'. I was wondering if smaller wheels would feel much diffetent.

Didn’t say what you were thinking...are you related to my wife?

Well, it’s not much use, but I do notice a difference in the car when my 18” winter set is on instead of my 19” summers. Ride is a bit softer, though I couldn’t tell you how much is the softer tire and how much is the taller sidewall. Maybe a bit of both? Same goes for lateral handling as well.

 

[dreamer]

I have 19s. Ride wise they are just great for a superb handling car. But all the 718s I had driven before this car had 20s and I could definitely tell the smaller sidewall created by the larger diameter wheel made for a better handling car. Of course looks are big and today was the first time I looked at the car and said “I wish I had 20s”. It looks fine with 19s but I think I like the looks of the car with 20s. Short of it....19s are practical, 20s are better looking and make handling better. IMO

 

[jimmuller]

Didn’t say what you were thinking...are you related to my wife?

Nit that I know of but I am married to mine. So I am familiar with the concept!