So i know this is a noob question, been outta the game a while so need a refresh. I have a 2015 is350 fsport AWD. Looking to get the similar setup of velgen vmb5 wheels 19x9 +35 and 19x10.5 +45. 235/35/19 and 265/30/19 tires. Lowering it on rsr downs or half downs not sure. I don’t want to rub or have issues with lights coming on, AWD system having issues


Question, for rear wheels, i don’t want ANY negative camber leaning in or out pretty much. I just want it flush. Will rear upper control arms help with this?

 

i had those exact wheels. I can confirm this:

1) 19x9+35//19x10.5+45----RSR Downs, you'll fit 235/35/19 (FRONT) 265/30/19 (REAR)----just FYI, i hated this setup lol. I did not like the stretch look and you'll be prone to cracking the wheels since you'll have very little tire to protect the wheel

2) 19x9+35//19x10.5+45----RSR Half Downs, you'll fit 245/35/19 (FRONT) 275/30/19 (REAR)---NOTE, you'll rub in the front when you hit minor bumps.

you'll have a nice fitment with the 2nd setup. no need for control arms and camber kits.

 

If you lower the car with the Downs the natural camber in the rear will be about -2.2 to -2.4 degrees...so if you're looking for the wheel to stand up straight you'll need something like SPC camber arms in the rear.
However, if you stand the wheel up straight then there is a greater chance the tire will contact the fender...the natural camber helps everything to clear.
You could adjust out some of the camber to about -1.5 degrees-ish, and still clear and the wheel will still look fairly stood up.
These cars are meant to have some camber in the rear and it won't wear tires odd...just make sure the Toe all around is good...that's what kills tires on these cars.

 

For the 2nd setup, why run 245 in the front and not 235 to avoid rub?

What about running 19x8.5 in front and 19x10 in rear?