225/255 vs 235/265 split... Your pick and why?

[Nate047]

Hey guys, I had to hit a rock on the road and got myself a nice little bubble on the sidewall of one of my front tires yesterday. 😐 Since all 4 are somewhat worn I'm gonna just replace the set, which brings me to the question at hand.

US 225/255 vs CSL 235/265 split. Pros and cons of each?

My car is used daily so I do care about comfort and overall balance. I am currently on a set of 225/255 PS4 (19s) and will likely replace them with the same. Wheels are CSL size ACS Type III so 8.5 front and 9.5 rear. I feel like the small gain in grip from increasing widths would be less noticeable to me than the likely increased harshness from shorter sidewalls, and the slightly lower overall stance due to the tire diameters being about 15mm smaller is not a big positive or negative, but slightly negative leaning in my mind. Suspension is Eibach springs and Bilsteins.

I need to move on this ASAP so I'd love to get some quick opinions from anyone who has run both sizes.

I know the differences are negligible but humor me. 😅

Thanks!

[Tbonem3]

Depends on wheel width.

8" - 225
8.5 - 235
9 - 245/255
9.5 - 265
10 - 275

I would absolutely go 235/265 in your case. It's a whole profile smaller, so faster, and a little wider with a sharper shoulder. A bit more nvh.

plus- "csl"


I don't think you can say more grip due to width. The wheel size is cheifly responsible in that aspect, and same wheel size for you, so no increase, but the shoulder matters. Stiffer being better.

eibach springs and billys are already harsh, but a killer combo imo, and leave you plenty of ride height even with smaller tires, probably looks better not to mention, again, faster.

you didn't mention diameter, but I wouldn't worry about the negatives with 235/265 if 18". If 19, and you drive often, you might tire of the harshness, but ps4s are much more comfy than the pss were, so it's not too bad. The ps4s make it just tolerable for me. I have bilsteins too though.

[QuickM3]

I went from 225/255 to 235/40/18 and 265/35/18 on OEM 18's. The difference wasn't massive. I did not notice any loss in comfort. The tires I put on were Advan Apex's. Good tire for the money. P4S would have been my first choice. The additional grip was more due to tires then the size. But I also like the look of the larger tires. I would never put 225/255 back on over the larger size. The more I write this reply im realizing you should go to 245/35/18 and 265/35/18. Not sure why you would consider 225 on the front of a 8.5" wheel. And 255 on a 9.5" is not helping you performance wise.

[Nate047]

^I wouldn't do sizing like that for a street car because the front tire is an entire inch shorter than stock and the rear is nearly an inch. Might be faster but it's gonna be more harsh, look a lot different in the wheel well, and lower the ride height by like half an inch.

I think I'm gonna go with the standard size because of NVH (I'm on 19s so it's already exacerbated) and to save a hundred bucks.

Also FWIW 225 PS4S are completely fine on 8.5" and same with 255 on 9.5" due to tread width being within .5" of wheel width. https://motoiq.com/how-to-properly-s...r-performance/

[QuickM3]

Oh I was thinking you were on 18" CSL reps. Sorry for the confusion.

[Rkymtnrider]

I’m planning on running 245/40 and 275/35 on 9x19 and 10x19in rims. Keeps the front to rear ratios the same and the tire is .6 inches taller. I know the tire sticky shows only smaller profile tires, but all my research says it should work fine.

[QuickM3]

^I wouldn't do sizing like that for a street car because the front tire is an entire inch shorter than stock and the rear is nearly an inch. Might be faster but it's gonna be more harsh, look a lot different in the wheel well, and lower the ride height by like half an inch.

I think I'm gonna go with the standard size because of NVH (I'm on 19s so it's already exacerbated) and to save a hundred bucks.

Also FWIW 225 is completely fine on 8.5" and same with 255 on 9.5" ... https://motoiq.com/how-to-properly-s...r-performance/

Now that I know you are on the 19", you can also do 245/35/19 front. its a -1.1% difference in height but you get significant more rubber on ground. Looks like alot of guys run that size on the 19's with no ill affects. Matched to 265's would make a good looking and performing car. But you will pay more.

And yes, you can even put a 215 on a 8.5" (those stance guys). I just figured we were trying to add performance!

[maw1124]

^I wouldn't do sizing like that for a street car because the front tire is an entire inch shorter than stock and the rear is nearly an inch. Might be faster but it's gonna be more harsh, look a lot different in the wheel well, and lower the ride height by like half an inch.

I think I'm gonna go with the standard size because of NVH (I'm on 19s so it's already exacerbated) and to save a hundred bucks.

Also FWIW 225 is completely fine on 8.5" and same with 255 on 9.5" ... https://motoiq.com/how-to-properly-s...r-performance/

I went to 235/265 on stock 19" 67s based on my experience with other cars and had ZERO problems at all... it's an occasional use car, but all street and some funny weather (mostly rain down to 40*F) so I use Conti AllWeather tires. I didn't realize the rear wheel was as wide as it is, and I'm thinking of going 235/275... posed a similar question in the tire sticky a couple days back. It looks like 235/275 would work just perfectly... I'm waiting on responses but I'm likely to have this done by the end of the month since I'll be vacationing with the car and this change will be Day 1 of vacation.

Basically one size wider than stock on the same aspect ratio should give you a slightly taller sidewall to go with the wider patch, which translates into handling + comfort with no ill effects as long as you stay within well known rolling diameter limits. The tirerack.com spec sheets are your friend here.

GL

maw

[cobra]

Heck I would go 245/275. I love mine, and running them on 18x8.5 fronts and 18x10 rears. They look perfect, not stretched or bulging. Big handling upgrade over the stock 225/255 as well.

[mtech9]

I've run both, (and others) - 225/255 looks the best so for that alone i would go with that

[Nate047]

225/40/19 PS4S have an 8.1 or 7.8 (BMW specific model) inch tread width so I don't see an issue on an 8.5 inch wheel.

I'm just doing the 225/255 again, I know how it fits and looks and rides. I'll also save like a hundred bucks.

[Sharocks]

I like having more sidewall, so I usually used to run:

245/35/19
275/35/19

[Tbonem3]

275/30/19

[m3nt0s]

Heck I would go 245/275. I love mine, and running them on 18x8.5 fronts and 18x10 rears. They look perfect, not stretched or bulging. Big handling upgrade over the stock 225/255 as well.

My wheels are also 18x8.5 and 18x10, but I made the mistake of going for 235/265 because I figured CSL sizing must be a good way to go. Unfortunately, the tires look a tad stretched on the wheels, which I despise, and I am definitely going 245/275 on my next set of tires.

[joshuatrueanderson]

Perfect timing for this thread. My wheels arrived today and havent pulled trigged on tires due to not knowing correct sizing going from 19" OEM to 18" aftermarket

I bought Enkei NT03+M

18x8.5 in front
18x10 in rear

Looking at Michelin Pilot Sport 4S for this.

Sounds like Ill be going the 245/275 route.