I'm running 215/55/16 "H" rated Grand Touring Tires. I'm considering purchasing some Ultra High Perfrmance Z or W rated tires in the same size. What kind of change can I anticipate in how my car drives? Will it still be quiet riding? Smooth? Comfortable. I know that I will have increased braking, traction and steering response, but will I feel like I'm riding on a really hard tires? Has anyone stepped up from a H rated "touring tire" to a higher speed rated "performance tire"? Were you pleased?

 

I went from the stock Good Year RSA's 215/55/16 "H" rated tire to 235/45/ZR17 (new wheels also of course)

Going from H to Z was quite a difference. They stick much better, steering response is dramitacly increased. Stability is much better. The ride is about the same, maybe a little bit harder large holes and bumps. It all depends on the tire as well. Read the feedback on Tire Rack before you make a purchase. Some Z rated tires are noisy and some are quite. My Dunlops (SP8000) are fairly quiet. The sticky rubber does throw up more road $hit like rocks and pebbles. I hear a lot of dirt and rocks being thrown up in my wheel wells. Aside from that, I'm pleased with the performance and ride on a Z tire.