I recently bought a used 03.5 sedan and put a set of Foose Speedster 20"s on it. Since I put on new wheels and tires, I've been feeling some vibration at around 65 mph. With the stock wheels, it rode smooth as glass. I can't tell if its a wheel balancing issue, or if there is just more "road feel" due to the bigger wheels/low profile tires.

Any thoughts?

 

Your wheels/tires probably need to be re-balanced.

Are those hubcentric wheels?

 

sorry, I don't know what "hubcentric" means.

 

if you look at your rotor, you'll see a ring around the axle nut. The OEM wheels actually use that ridge to center the wheel, not the lugs. Aftermarket wheels need rings because the center is large to accomodate various makes of cars, and lug holes alone are not enough to center the wheel properly. Perferrably metal rings.

If you have hubcentrics, find a Hunter Roadforce balancer in your area.

http://www.gsp9700.com
enter your zip code.

This machine uses a roller to simulate the road and will find out of round tires or sidewall issues. Even radial pull on the new models.