vu.q.le

Resides the fact that 17's tires are cheaper, what is the ride quality differences on the street?

Mark I

Assuming by quality you mean smoother, it is significantly different. If you're focusing on comfort, 17" is a good option.

Rubik

Basic rule of thumb is that as your tire profile goes down, the level of comfort also goes down. You begin to feel all the cracks in the pavement even more so than you do with a higher tire profile. But the handling does become more rigid and responsive since the lower profile tire side walls are a bit stronger. My recommendation is to look at your street conditions and your driving style and make a choice. My owns are 18" and I love the handling but the ride does get bumpy, especially on LA streets.

King_James

I have 19s and my car is lowered and it's smooth and comfortable, honestly I couldn't tell the difference between 18s and 19s. If you're on 17s now I suspect 18s won't feel any different at all.

vu.q.le

If I switch from 18 to 17 or vice versa, do I need to get the speedometer calibrated? Or the car electronics should adjust accordingly ?

5CHN3LL

Just choose a sidewall to match the original geometry and you won't need to worry about the speedo. The car will not adjust accordingly...

Rubik

Talking about geometry, the 295/30 18 has a speed variation of 0.25% compared to the stock 255/40 17. But the factory chose 285/30 18 which has a higher delta of 1.09%. I wonder why they did that? Was it a fitment issue with the 10" wheels? vs. 11s?

Arne Klinge

I have 17" for winter tyres, they are significantly more comfy than my 18" summer tyres. But again the 17" look like balloons compared. I live in Bergen in Norway and we have cobblestone all over, feeling those 18" every time I drive into the city, not so much with the 17".

tokyopav

I put a set of 295x40x18" Alpins on for my winter rims. My summers are 285x30 so the extra width x profile on the winters did make a noticeable difference. Still not balloons and the extra width on the winters look pretty awesome. Maybe just a fatter tire with a taller profile is the solution.

33jacket

what size 19s are you running in the rear (tire and rim)

Barn996

I also run 17s for the winter and initially ran 17s for summer tires as well. A few years ago I bought some 18" wheels for summer only and did notice a degradation in ride comfort compared to the 17s. Can't notice much difference at higher highway speeds, but IMHO, the around town driving is harsher, but not to the point that I would change back to the 17" wheels. Personally, I'd have difficulty running 19s based on my experience. Hope that helps the OP.

2002C2

hey tokyopav, just curious why you would run wider tires in the winter. Even with the higher profile you reduce the weight per suface area which I would think you'd want to increase in the winter.

tokyopav

2002C2, we don't get much if any snow here in Tokyo. I prefer the look over pure performance and given the excellent performance of the michelins I was happy to accept the trade off if any, mostly driven on really cold and wet days, yet to break traction with the winters and the size really do look awesome.

PORCAR

No because I have Porsche accessories wheels and they are 18X11, 295/30.

And to answer OP's question, I would stick with 17''s. The ride is much smoother and the street difference on an identical model max-perf tire is nil. But if you are running the stock suspension, that is horrible in both sizes, imo.

Ck986

I didn't notice any difference in ride quality going from 17's to 18's in my 986. In the turbo the 18's are a little harsher.