go back to 18"s
I started out with OEM 19"s which came with conti sport contact tires. They were noisy and rode hard. The dealer was nice enough to let me trade out for a set of OEM19"s with Pilot Sport II's. They were softer riding but just as noisy. I switched those to Yoko advan sports. Much quieter but harsher riding-I am ok with that. Of the three 19" tires that fit the stock wheels (there are not that many) the pilot sports had the most comfortable ride. Good luck with your quest....