Just purchased a 2015 IS f sport and lowered it with RSR down springs and installed 20X8.5 et 35 with 225/30/20 tires and 20X10 et 40 with 255/30/20 and have a slight rub in the rear over big bumps. Do you guys with the 40 et rear offset have this problem? By the way the RSR down springs ride great! i will get the vehicle aligned next week, should i have the tech run a little more neg camber in the rear if possible. Thanks

 

Running 19x9.5 +39 in the rears on mine.
Stupid mistake I did was going with 265 Michelin PSS on mine and yup, rubbing occurs on big dips.

Unfortunately, there's no camber adjustment on our cars from factory, so you'll need to run an aftermarket camber kit if you wanted to dial out the camber.

There's also nothing to roll in the rear either so yeah... it sucks.

 

Thank LexSense, as i read more i found that there is no camber adj on the rear. I will order the Figs rear camber kit and see how it goes. Thanks again

 

I looked up in the rear fenders today and noticed several bolts protruding into the wheel well (I'm assuming they hold the quarter panels on or something)

What did you guys do with those to help with the rubbing issue? Shave em' down? Can't cut em' off I know that much.