I've got 20's and my ride really isn't that bad. I am running Falcon 245/35/20 tires front and rear on an 8.5" rim. I did not drop my car either. The ride is a little more harsh than before but if I had to do it again, I would still get 20's. Go for it. BTW there will be plenty of haters and they will push 18's like they are the next big thing. I'm happy w/my 20's.
You can't beat 20's. What you lose in smoothness (very slight) you more than make up for in overall rigidity and control as you drive.
I went with 245/35/20 and the ride is awesome. No rubbing and I drive a lot. The only thing you may incounter is rubbing with the rear fenders, but that's only when you hit a bump and have the trunk or rear seats heavily weighted.
You need to do some research at this forum on the safety and wear of 20" rims.
I started out w/ 225x55x17". Tried 235x40x17" it looked silly and really affected the harshness of the ride. Now I have 245x45x18". The ride is harsher. As the sidewall becomes shorter the ride becomes harsher. A 35 series will ride harsher than a 45 or 55 series. I suggestion is the 245x45x18" just like on the CTS-V
We had one member with 20" rims that his camber was out so far they couldn't be adjusted. Check Camber in the search mode. You might find the thread.
This is actually almost a very "laughable situation". I've heard the word, "application" from forum members acting as suspension geometry and brake specialists and now were learning about problems with scrub radius, rear tracking, negative camber etc, etc.
I guess "application" and "engineering limits" with regard to suspension geometry are mutually exclusive items at Cadillac dealerships such as Allen, Lund, ABC, and XYZ Cadillac.
I guess all of those expert GM Dealership Technicians that installed those 20" rims and rolled the fender wells lips to fit 20" of aluminum alloy in a 10 pound bucket tub were really Ford suspension geometry experts moonlighting as mechanics at Cadillac dealerships with the sinister intent of destroying the CTS suspension.
Right after installing those 20's and slamming the suspension to the ground and tossing my Nivomats in the dumpster in favor or a softer dampening luxury shock, I'll be sure to jump on that GM service tech's advise on the ceramic and Hawk HPS brake pads as being "rotor aggressive" in lieu of the soft compound OEM front pads on a proprietary cryo treated rotor that they have never seen.
I'm not quite sure that I ever heard of the CTS front sport pads referred to as a "soft compound pad" in the 3 volume 1800 page CTS technical manual anywhere that I have read cover to cover at least 3 times where there is a "specific caution" of not to install a wheel rim greater than 18" for the exact reasons described above!
But I guess the GM and outsource engineers that designed the suspension geometry of this top shelf CTS suspension system really just don't understand the "application, application, application".
I guess to understand the engineering limitations and paramaters of suspension geometry, they would have to have read past page 3 I would assume.
But then again, that same GM tech would probably explain a solid one piece cross drilled rotor acting as a "thermal heat sink" with an oversized and VERY WRONG SIZED 20"wheel rim contributing unsprung weight and disturbing the vehicles suspension geometry as probably something really warm that you wash your hands in......(aka: thermal heat sink)!
First visual sign as we both know is the tires......most don't have a clue as to the progressive damage that they are doing to the suspension hardware of their vehicles with those 20" wheel rims, Eibach lowering springs and luxury shocks. But they are looking awfully damn cool turning that CTS tuned sports suspension into an advertisement for Low Rider Magazine:histeric: