Ride quality between differance between 35 - 40 - 45 Series tires
 

Is there a big differance between going from a 235/45-17 to a 235/35-19 when it comes to ride quality? It is a lot more harsh?

What about 235/45-17 to a 235/40-18?

My car came with 235/40R-18's and I have my winter setup on 235/45-17's
 

The ride with my 17's (45's) is a little bit nicer than with my 18's (40's). I think I can tell a little bit, I don't think it's major.

Rule of thumb: The shorter the sidewall, the less flex you will have....
 

and the less cushion you will have to absorb the roughness of the road. Also the lower profile, the greater chance you have to having tire damage due to adverse road conditions. I run a 245/40/18 and I will not go any lower profile. You will notice a lot of difference as the profile goes lower, especially if you are on sport suspension or COs. But everyone can handle the roughness different, so you might find friends with the various aspect ratios and go for a ride.

Hmm...so 35 series would probably be real noticable if 40 serires is a little bit.

Yeah.. you might. My 40's with sport suspension is rough enough for me.

minor diff. I can barely tell on my sport susp, nor COs...
 

on the 17's you are talking a 105.75mm sidewall
on the 18's you are talking a 94mm sidewall
on the 19's you are talking a 82.25mm sidewall

the difference between each wheel size is about 1cm of sidewall, which makes sense, cause when you go up an inch, the side wall will decrease by half an inch ~ 1cm.

Now go get a ruler, and tell me that you are going to be able to TOTALLY tell the difference in 1cm of sidewall.

What will make MORE difference, different brands of tires, or 3Lbs of airpressure.

If you live in an area with decent roads, have the $$$, and like the way 19's look. Get some good ones, LIGHT ones... And when you roll up to meets park next to a guy with 18's and just smile. : )