The tires on my car are making a lot of noise and the ride is a bit harsh. It has 18-inch run-flat tires. Is this normal? What can I do to improve the performance and make them less noisy?
Unfortunately, yes, this is normal for "run-flat" tires. In order to be able to run flat, they have very stiff sidewalls to support the vehicle when there is low/no air pressure in the tire. Check out major tire outlets (like Tire Rack) that share surveys on the Internet and comparative research of different tires in your size. You may find another brand or model of tire that is still run-flat but makes less noise. Take the car into a local tire shop to have the tires checked and the sound-tested for.