Achtung, Achtung, Tire Choices and an important caution!

[WillyDaP]

I am pretty sure you will find the 660+ better, and heck even if it is only equal check out the tests, it comes out ahead of the SC3 --- now the SC3R is another story, but not the right sizes for many Porsches .

[rbpeirce]

I have swapped the SC3 in the past.

I just noticed the 660+ is directional so side-to-side swapping won't work unless it is ok for the tire to run backwards. I've heard that may be true. If not, I would have to unmount/mount/balance the tires on the opposite wheels which would be pretty expensive. OTOH, with more camber I may find swapping isn't necessary. I'll know that before I have to order another set of tires.

[rbpeirce]

I am pretty sure you will find the 660+ better, and heck even if it is only equal check out the tests, it comes out ahead of the SC3 --- now the SC3R is another story, but not the right sizes for many Porsches .

The 660 did but the 660+ is new and I haven't found any tests yet. I expect I will before I need to order another set of tires. Also I will know if swapping is going to be necessary or not.

[WillyDaP]

Same compound or better, same tread design, different interior carcass design, so I would sure hope they are a bit better, but like you I have not seen any actual tests.

I may call Luke Pavlik ( ext 4362 ) next week at Tire Rack as he was our Rep for our Motorsports Division at Woodhouse Chrysler, Dodge , Jeep, Ram and Woodhouse Ford and he is an active track and autocross guy there. I have known him for 26 years and he is one for great advice for Track and Autocross junkies. He may have a sneak peak on the RT660+ but you do have a couple other killer choices depending on whether your concern is overall stickiness or wear, ha!

[WillyDaP]

Part of the reason I am suggesting chatting with Luke or maybe waiting for tests as rbpierce mentioned is I am pretty convinced Falken has made some big changes as very aggressive drivers have noticed a peeling away of the outside edge or center rib with the 660. Falken, like many Manufacturers tend to do, did not acknowledge the problem, but the interior carcass and bands were redone lending one to believe they did know of the issue and are addressing it. Many folks did not have any issues with the tire, possibly as they rotate the tire often. Let me note this tire is not my favorite , but over the years playing on asphalt I have seen issues with BFGs, Michelins, Pirelli Corsas, etc. so I tend to be a bit more realistic that tires need the kind of care on track/autocross as we normally reserve for oil changes and other common maintenance for track/autocross use. I actually have a couple other favorites over the Falken, but I commend them for redoing the tire and it may prove to be a sleeper?

[SapphireRacing]

One of the few things that bug me about 718 non-GT4 is the stock tire sizes because it’s difficult to get any other width close to the factory diameter. I’m about to have some custom wheels made so I can achieve the combo of design and color plus light weight and optimal width with 235/40-19 and 265/40-19.

Really wish Apex made 19s in stock width, but alas they don’t and fitting stock sizes on their 0.5” wider wheels is too much stretch IMO.

[WillyDaP]

Honestly if you are not autocrossing in a Stock Class the 9 inch wheels that Apex offers in front is a better choice imho. With those up front and 10.5s in the rear a set of 255/35/19 Bridgestones fit just fine, along with 285/35/19s in the rear. I did get a little bit of negative camber up front , but I know a couple of guys who just maxed out the factory amount with no issues. It isn't much, but honestly a 255 fits on a 9 inch better and I believe that was their thought process at Apex Wheels.

Good luck and I have a set of 18 wheels also and with a Tarett front camber plates ( -2.25 up front ) I had a set of Hoosiers A7s on them ( 255s/35/18 and 295/30/18s ).

Just think about the GT4 with a size wider up front and two sizes in the rear over a GTS, those tiny rubber donuts are just part of the Porsche plan to not let the GTS be quite close to a GT4 --- smaller rotors, smaller wheels and a slightly tuned HP . So many performance cars do the same thing to differentiate their models. Mustangs have been hilarious with their tiny tires on a GT ( or other models ) and once you move up to a Handling Package Option they slap on some larger meats with not problems.

[SapphireRacing]

Honestly if you are not autocrossing in a Stock Class the 9 inch wheels that Apex offers in front is a better choice imho. With those up front and 10.5s in the rear a set of 255/35/19 Bridgestones fit just fine, along with 285/35/19s in the rear. I did get a little bit of negative camber up front , but I know a couple of guys who just maxed out the factory amount with no issues. It isn't much, but honestly a 255 fits on a 9 inch better and I believe that was their thought process at Apex Wheels.

Good luck and I have a set of 18 wheels also and with a Tarett front camber plates ( -2.25 up front ) I had a set of Hoosiers A7s on them ( 255s/35/18 and 295/30/18s ).

Just think about the GT4 with a size wider up front and two sizes in the rear over a GTS, those tiny rubber donuts are just part of the Porsche plan to not let the GTS be quite close to a GT4 --- smaller rotors, smaller wheels and a slightly tuned HP . So many performance cars do the same thing to differentiate their models. Mustangs have been hilarious with their tiny tires on a GT ( or other models ) and once you move up to a Handling Package Option they slap on some larger meats with not problems.

I have a set of Apex wheels with 255/35-19 and 285/35-19 tires on them. From a width perspective those sizes are perfect (don't want too much rear grip for a street car).

However, continuing to think about the 1.8% difference in diameter underscores my irrationality in considering very light custom wheels merely to revert to the original tire sizes.

Note that the ride height difference does make a noticeable impact in a couple scenarios:
1) entry angle to driveways
2) scraping the wheel air deflectors when the car is loaded up cornering on undulating pavement. I heard this on a backroads run and was worried at first that it was more serious. See pic below:

PXL_20250123_222125140.jpg (223.63 KiB) Viewed 3466 times

PXL_20250123_222156858.jpg (224.92 KiB) Viewed 3466 times

[J-Dub]

Just in the off chance this makes you feel any better myself and many others have went to the GT4 size tires on our non GT4 718s and that has no trouble at all, they are well within the cars workable range.

In fact those tires sizes, especially in the rear, make the car look so much better. The 265s looked stretched on the stock wheels, I keep my stock wheels as my street wheels and bought a set of 19" as track wheels. Like Bill I also use the Bridgestone 255/35/19 front and 285/35/19s in the rear.

One of the few things that bug me about 718 non-GT4 is the stock tire sizes because it’s difficult to get any other width close to the factory diameter. I’m about to have some custom wheels made so I can achieve the combo of design and color plus light weight and optimal width with 235/40-19 and 265/40-19.

Really wish Apex made 19s in stock width, but alas they don’t and fitting stock sizes on their 0.5” wider wheels is too much stretch IMO.

[blueline]

Just in the off chance this makes you feel any better myself and many others have went to the GT4 size tires on our non GT4 718s and that has no trouble at all, they are well within the cars workable range.

In fact those tires sizes, especially in the rear, make the car look so much better. The 265s looked stretched on the stock wheels, I keep my stock wheels as my street wheels and bought a set of 19" as track wheels. Like Bill I also use the Bridgestone 255/35/19 front and 285/35/19s in the rear.

One of the few things that bug me about 718 non-GT4 is the stock tire sizes because it’s difficult to get any other width close to the factory diameter. I’m about to have some custom wheels made so I can achieve the combo of design and color plus light weight and optimal width with 235/40-19 and 265/40-19.

Really wish Apex made 19s in stock width, but alas they don’t and fitting stock sizes on their 0.5” wider wheels is too much stretch IMO.

For the GT4 I run 265/35 ft and 295/35 or 305/30 rear on the 19" Apex forged wheels (19" x 9" and 19" x 11").