So I have the stock wheel and tire sizes on my 09 IS250, Michelin 225/45 ZR17.
Will changing wheel and tire size cause me problems, Why would I want to change? All my wheels have some scraping if not from curbs, it could be from the drive through car washes I go through 3 times a week
I did a little search and while looking at Tire Rack Dot Com they rate this one the best (I think?)
Vredestein Quatrac Pro 225/45 R17

Sorry for sounding and being a ROOB... I have only owned this little beauty for about a month.

 

Make sure your front and rear tire sizes are the same. MANY 2IS owner (like myself) have a staggered setup (front wheels are narrower than the rear), which means different tires front-to-back.

Anyhow, being in MN, I assume you need a good all-weather tire. Though the mentioned tire is highly rated, it has a lower treadwear (tire life) when compared to others. I sorted by price and found multiple cheaper options by good brands. If Tire Rack has no feedback on the tires on their site, just hit up Google for some opinions.

 

all the same on this one...

 

Is the reasoning to change wheel size mainly just for a look? Is there any advantage to changing it? I would think there would be less sidewall of the tire which would take away from ride comfort? The actual circumference of the tire should remain the same as a stock tire to keep the speedometer accurate, correct? Sorry for lame questions or points, I just don't know...

 

Sort of.

Yes, as I do, I run lower profile tires to maintain less "tire-rollover" when in corners. More confidence inspiring than a tire that rolls over and you never can quite get a sense of what it's doing when. Just being more consistent I guess in the corners.

Yes.

Yes.

You're on the right track. No need to get a different tire size unless getting different wheels or a different suspension setup. Lower profile tires on a stock suspension 17" wheel-equipped 2IS wouldn't look right.