I recently put on my summer wheels and tires (Steeda Ultra-Lite II 18x9.5 chrome wheels w/ Nitto NT555R 285/35/18ZR Drag radials), and I've noticed that whenever I reach speeds of over 70mph, it starts to get a mild vibration. Doesn't seem to be isolated to either side or either end, just the entire car up and down slightly. The only thing I can think of is that they may need to be rebalanced? I've had them for 2 years now, don't know what else could be the cause.

 

the first thing I would do would be to get them balanced. That's usually the case 99% of the time with vibration at high speeds (like on highway). If that's not it, we can then at least get that out of the way.

 

Yeah, got them balanced, fixed that right up!