I have stock wheels on my 1997 DeVille. I want to go to a 20 but I have heard a few things that is really making me think twice about doing that. I have heard that breaks and suspension wear out faster, and I heard that your ride quality is degraded. If anyone has any answers please help me out.

 

Yes, it is possible that your brakes may wear out faster, and possibly your suspension also. Ride quality can be degraded as well.

With the larger wheel, you have more rotational inertia, meaning more unsprung mass (more mass not suspended by the car's suspension), and therefore your brakes have to stop more mass from rotating you apply the brakes. If you don't drive agressively, you might not see too much brake wear. However, braking is also a function of air ventilation to cool the brakes, so typically larger wheels allow more air flow and better brake cooling (if the wheel has large openings). It's complicated system with numerous variables. You may upgrade your brakes and avoid the problem altogether.

As far as ride quality goes, the lower in tire profile you go, the less amount of rubber you have between the ground and your car's suspension, and therefore you have less of a rebound effect, making your ride stiffer. I would try to take a ride in someone else's car, similar to yours with similar tires, if possible, to feel it's effect.