I’m at the point where I have a baseline setup I’m confident with, now it’s time to experiment and see if I can find something quicker. :iono:

It likely depends on the exact tire you're running. Some 225s are actually closer to 245 and would fit nicely on a 9" wheel.

Can I ask you guys a tire question.

This is my first rwd car and after running 1.5 seasons in DS I feel more confident and starting to feel the limitations of the stock Premacy tires.

I am now starting to think of buying a proper set for next season. Either RE71 or RT660, depending on what kind of deals I can get.

The question is which size would you recommend. I am keeping stock 17" rims for now:

225/45R17

or

225/50R17

Would the second one fit without rubbing? Would the higher sidewall cause more flex at AutoX and reducde performance?

The reason I'd like to get 225/50 is more ride comfort because I daily this car and the roads around here are pretty bad.

Thank you

I'm running 225/45/17 660's on my autocross wheel set. I don't run that wheel/tire set full time, but I do have a 45+ minute drive each way to/from events and cross over a wide variety of rough road and highway surfaces. I also took them on a 2+ hour backroad drive to wear off the mold release right after they were delivered. I actually find the 17" set to be smoother riding and a bit more comfortable than the OEM/factory 18" Pilot 4 set I drive on daily. I'd happily drive tires that size in a daily situation.

What I WOULD worry about is rain performance of of those tires in a daily driven situation. Although I have driven the 660's once in pouring rain with a small amount of standing water, I did drive very carefully/timidly and well below the speed limit on the highways. I'm not sure that is something I'd want to deal with every time I drive the car in the rain. 660's are a good tire, but I wouldn't daily drive them for this reason. You may want to look at the Bridgestone's or maybe the Yokohama's which may have better water evacuation than the 660's.

EDIT: Just looked at the 225/50/17 size compared to the OEM 215/45/17 size on a tire size calculator. The 225/50 tire adds 15.8% more sidewall and make the tire 5.3% larger in diameter (1.3" difference). At highway speeds your speedo would read 2.5~3.7mph low depending on how fast you were driving.

Did you mean 225/50R16? The RE71 and RT660 are not available in 225/50R17. I run the RE71 in the 225/45R17 size (2022 BRZ). I don't notice much difference in ride between them and the Primacy, so must not be that sensitive.

For autocross, you will see a huge difference. I autocrossed on the Primacy for one event when in my 2015 BRZ, and I almost gave up on the whole "street" tire concept due to how bad they were (I had only driven on Hoosier and Kumho autocross tires previously). I have been on Bridgestones RE-71R and RE-71RS since, and am happy with their performance.

Oh wow, you are 100% correct. Maybe I was confusing them with the 16" ones.
Well I guess this makes this a pretty easy decision, 225/45 is the only option

Thank you for your input
I heard guys from my local autox club say that they are decent in rain as long as theres no big puddles of water, then you might be in trouble. I drive pretty short distances and not much highway driving so I think they should be fine.

I guess I'll be the one to ask... why so narrow? The 245/40R17 fits and will probably be faster.

The size is definitely used by some people in DS.

Good question. I guess I am worried it will make it a worse daily driver (tramlining, worse performance in rain). Tires would also be stretched on the stock rims which is not ideal.

I am considering compromising with 235 maybe... I see that Bridgestone has 235/45 and Falken even has 235/40 available

I'd never buy the Falken and the 235 Bridgestone is *really* tall so that's not ideal.

245/40R17 Bridgestones would be my choice, even considering the daily driver use.

Personally I've only seen people on the shorter 245/40/17, not the 45.

Falkens do seem to be much cheaper, although I've heard guys say that sometimes you can get a deal on Bridgestones.

If you recommend it I will definately consider it. Is it 100% known that there ll be no rubbing anywhere under any conditions with this size?

I run 225/45/17 only because it's what you can fit on stock wheels with a +48 offset, even with a small slip on spacer. 245 needs less offset via wheels and spacers to work, which I didn't want to do thinking of going to STX long term. If you are sticking with stock wheels, I'm pretty sure 245's aren't going to fit.

Tramlining is usually from excessive camber and other things like toe. People have 275+ tires (not on these cars), so if the larger the tire directly correlated to tramlining and terrible rain performance, everyone wouldn't go above a certain size. Which if you're in DS, you won't have any tramlining issues.

IMO, if you want to be competitive, 245's are necessary. My car is off pace, even with other drivers in it. When it rains however, mine can match or even exceed 245's... and a gen 2's time with a GOOD driver. But for 90% of events that are usually dry, 245's are the ticket.