Hello, I have a 2014 is250 running 225 40 R18 front and 255 40 R18 rear with stock wheels(the first pic is the same wheels I have now).

Looking to get the Avid AV-32 18x8.5 with ET 40 in the front and rota torque r 360 in 18x9.5 with ET 30 in the rear. I need to replace my front tyres soon, and after doing some research seems like getting 235s in the front and keeping my 255s in the rear is a decent choice for upgrading all the wheels in the future. The aftermarket wheel specs I have chosen could be wrong, and I welcome any advice(my first time).

AVID AV-32

Torque R 360FF

Current wheels

 

Hey sorry I didn't order the pics correctly. the last pic of the silver IS are the wheels i have on now.

 

^^ This is just my opinion but have you considered putting the OEM F Sport wheels on your IS? The twin spoke design is the best looking design out there (IMO) and would look far classier than these aftermarket wheels (no offense)

 

If you are going to go aftermarket, you would want forged wheels. While I like OEM, they are heavy, and reducing unsprung weight is such a nice performance enhancement.

That said the offsets you are considering are wonky. Here are the specs I ran on my RC350 which is similar or pretty much the same as the IS. 19x8.5et34 (245/40) and 19x9.5et40 (275/35)

A 255 width tire is going to be stretched on a 9.5" wheel. Also if you are AWD, you want to maintain the same diameter front to back, so a 235/40 would go with a 265/35. I would be shocked if you current setup is 225/40 and 255/40 as the rear tire would have a much higher sidewall.

Below is a pic of my 245/40 and 275/35 for reference. If near NY, I have the setup for sale too as I sold the RC