Does size REALLY matter?

[Stoicc]

I have 20x9 and 20x10.5 staggered wheels for my 2019 GT2 AWD Stinger.

I was initially looking at getting 245/35/20 +35mm front and 285/30/20 +45mm rear.
What would the difference be if I went with 235/35/20 and 275/30/20? Will this still be ok with the wheels I have or should I go with the bigger sizes? What offset should I get if I do go smaller?

My car is lowered on the Eibach Lowering Springs and I do not want any rubbing to happen as this is my daily driver.

 

[Kamauxx]

The first thing that comes to my mind is 10.5" wheel on 275s will stretch the tires out. Some people actually like that look though so you may want to google pics of those sizes together to see how you like it.

 

[shaggystinger]

What you are initially looking at for tire sizes is correct for your wheels sizes and you should have no rubbing or issues lowered on eibach springs. As Kamauxx said, for a 10.5 wide tire, 285/30/20 should be the absolute minimum otherwise you'll have a stretched tire and begging for curb rash on those wheels. The offset you have for the wheels is also spot on.