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Let's try that again.

stock 19": front - 235x35, rear 265x35, rear diameter to front diameter ratio 1.032
track 18": front - 235x40, rear 275x35, rear diameter to front diameter ration 1.007

As long as the front diameters are a little smaller than the rear diameters (which is true for either front tire you are considering) you are ok.
 

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Discussion Starter #22
Let's try that again.

stock 19": front - 235x35, rear 265x35, rear diameter to front diameter ratio 1.032
track 18": front - 235x40, rear 275x35, rear diameter to front diameter ration 1.007

As long as the front diameters are a little smaller than the rear diameters (which is true for either front tire you are considering) you are ok.
Thanks for this. Really appreciate the time and patience to explain. Good to learn and hear about these ratios.

I'm adding 7mm and 14mm for the front and rears, I don't suppose adding spacers will affect these ratios.

BTW, you have a great stable of rides. How's the streetfighter? I'm hesitant to get back on a bike again but have always liked bikes. Have you tried a Confederate?
 

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Spacers will not affect the tire diameter or the PSM operation.

Thanks for the compliment. I don’t ride the Streetfighter as much as I’d like, work gets in the way.

The Confederates look cool; I think the Streetfighter is a better value. Less weight, more power, much less upfront cost and a dealer network for support.
 

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Wow...after reading this, I've got a couple of comments...I had an '06 CS fo 10 years.

1. They don't make 235/40/18 PSS anymore? I had them on my car...but I also had PSS on the rear...stock sizes.

2. PSS is a different sort of tire from PS2. For a daily driver, it won't matter too much, but I'd go with PS4 or PS2 to match the rears. PSS are not current tech either...and if they don't come in 235 anymore, I wouldn't change to them just to have newer tech...They've been discontinued too. PS4 is the new black.

Again I wouldn't change to a narrower tire just to get PSS.
 

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Discussion Starter #25
Wow...after reading this, I've got a couple of comments...I had an '06 CS fo 10 years.

1. They don't make 235/40/18 PSS anymore? I had them on my car...but I also had PSS on the rear...stock sizes.

2. PSS is a different sort of tire from PS2. For a daily driver, it won't matter too much, but I'd go with PS4 or PS2 to match the rears. PSS are not current tech either...and if they don't come in 235 anymore, I wouldn't change to them just to have newer tech...They've been discontinued too. PS4 is the new black.

Again I wouldn't change to a narrower tire just to get PSS.
Agree on PS4S being the newest tech. Thing is, I can't get PS4S in 18s where I am and shipping them in from the USA will just make the cost silly. So next up is PSS and yes, discon too so its old new stock I'm referring to. Not knowing too much about these things, one of my proxies for tires right or wrongfully is the tire rack survey and after PS4S, its the PSS.

Once the local agent decides to bring in PS4S for 18s on a non indent silly pricing basis, I'll definitely consider them.
 

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Discussion Starter #26
So for discussion sake, say a I move my rears to PSS 265/40/18 and have PSS 225/40/18 front.

Ssame brand, same model, rear size is per prescription but front is still very slightly narrower in width (prescribed is 235/40 while PSS is 225/40).... less "bad" then but still not ideal?
 

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If you're just driving the car to work and such, it won't matter. Don't fret over all this. I'd go with the newest tires you can find in STOCK sizes. Don't worry over if they have N-code or not. Get a decent rated tire, same kind on all 4 wheels, in stock sizes and be done with this. Not worth this much thought, really.

I don't understand all the constraints of buying tires in Mallorka. I'd say, if you can't get what you want there, go somewhere else and get the tires. Can you order from EU?

If they're narrower in front, it will affect ultimate grip a little bit...also diameter will be a bit smaller....so the traction control will be a little confused. The early Caymans had issues if you played too much with tire diameters front to rear but 10mm of width is only 4mm of sidewall height X 2 (radius, not diameter) so 8mm difference in diameter between 225 and 235.

PS2's don't ride very well. That's a consideration. They stopped making them several years ago...that's another consideration. PSS ride pretty nice but the date code matters. Rubber degrades and the the tires don't work as well when they're old...or ride as well. When very very old, they can be unsafe..

PSS, btw, aren't great for track use, but great on the street. When they get hot or hot pressure rises above about 38 PSI, they start to loose goodness. (as you heat the tires up with laps and as the track gets heated by the sun during the day, tire temps go up. You have to let air out as a track day goes on and check HOT pressures...different from cold pressure/street use. ...but that's not your concern here...Sounds like you just want some good all-around tires for driving around. Any of the solutions you've come up with will work OK for that. I like to have stock sizes on Porsches for a lot of good reasons. Suit yourself and your surroundings.
 

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Discussion Starter #28
If you're just driving the car to work and such, it won't matter. Don't fret over all this. I'd go with the newest tires you can find in STOCK sizes. Don't worry over if they have N-code or not. Get a decent rated tire, same kind on all 4 wheels, in stock sizes and be done with this. Not worth this much thought, really.

I don't understand all the constraints of buying tires in Mallorka. I'd say, if you can't get what you want there, go somewhere else and get the tires. Can you order from EU?

If they're narrower in front, it will affect ultimate grip a little bit...also diameter will be a bit smaller....so the traction control will be a little confused. The early Caymans had issues if you played too much with tire diameters front to rear but 10mm of width is only 4mm of sidewall height X 2 (radius, not diameter) so 8mm difference in diameter between 225 and 235.

PS2's don't ride very well. That's a consideration. They stopped making them several years ago...that's another consideration. PSS ride pretty nice but the date code matters. Rubber degrades and the the tires don't work as well when they're old...or ride as well. When very very old, they can be unsafe..

PSS, btw, aren't great for track use, but great on the street. When they get hot or hot pressure rises above about 38 PSI, they start to loose goodness. (as you heat the tires up with laps and as the track gets heated by the sun during the day, tire temps go up. You have to let air out as a track day goes on and check HOT pressures...different from cold pressure/street use. ...but that's not your concern here...Sounds like you just want some good all-around tires for driving around. Any of the solutions you've come up with will work OK for that. I like to have stock sizes on Porsches for a lot of good reasons. Suit yourself and your surroundings.
Thanks for the considered reply Sixi. Much appreciated. I've gone on the PSS fronts 225/40. I actually think they are better from the short drive today than my PS2 235/40. Could be because my PS2s were 4 plus years old and coming close to well worn. PSS being NOS are more than half their age and of course, no wear. With the B8 and Cayman R springs, I seem to be able to take the usual corners slightly faster than before. B8 R springs, PSS or both? Not too sure but for sure the PSS seem very ok until they aren't I guess.
 

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Both
Not surprising, always loved PSS tires. Had them on my 04 BS and currently on my Vette. Like them better than highly rated and thought of PS4s.
 

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I was on my way out of town a few years ago and had a Michelin go bad. I could not find one in town so settled on a pair of Conti all seasons for the front. Have summer Michelins on the back. No issues but I do not drive fast on the street.
 

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Discussion Starter #33 (Edited)
tyrereviews.co.uk

Very good tyre reviews. Take a look! Comments on different sizes, mixing, brands,wet,dry, performance etc. Great videos on youtube.
Thanks. This guy is good. I liked his review of the PS4S.

Looks like Goodyear is a consideration but it has 235/40/18 and only 275/40/18... lol... can;t seem to get prescribed sizes in alternatives for stock 18 wheels.
 

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Discussion Starter #34
If you're not going to track the car, nothing to worry about, you'll never know the difference!
I was on my way out of town a few years ago and had a Michelin go bad. I could not find one in town so settled on a pair of Conti all seasons for the front. Have summer Michelins on the back. No issues but I do not drive fast on the street.
Yeah.. so far, I actually prefer it to the PS2 fronts. While I understand why staying on same brand, model and prescribed sizes makes sense and is best, I think its perhaps also not absolute provided you don't go funky and have different brands/model on all 4 wheels or different season or too different specs ie widths, diameter aspect ratios etc.

On the next B-road drive and spirited freeway run is where the real test will come. I'll be sure to exercise a lot more caution and back off if things don't feel right.
 

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I have a 2014 CS and have PSS inhe front and Pirelli PZero in back. No problem at all. However, I’m close to change the back and when I will, I’ll get Michelin in the back as well.
 

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Discussion Starter #36
Have been driving the PSS PS2 setup now for a few days. Just installed my spacers yesterday and I'm liking how it rides even more now.
 

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Because of the new tires; not the spacers
 

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Well it’s a-bit wider 0.5” which will help handling
 
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