Hi everyone, been awhile since I've posted but I've got a problem that's driving me crazy. I have a full bolt on 02 gt, fresh fully rebuilt motor, fully upgraded cooling system. I put a 180 thermostat and was instantly happier as I live in California so the colder temps help with the overall performance. The car usually hovers around 179-190 when crushing in about 80 degree weather. Now heres my issue, as soon as a little traffic hits, or it's over 80 degrees outside, the car will start hovering at 200-210, which is normal and far from overheating. The problem is that as soon as the car goes over the 195 mark, I can feel a drastic change in performance and exhaust note. I don't even look at the temp gauge when I notice the car feels different, so I know it's not placebo. Everyone always talks about how bad 160 thermostats are but never give a reason, my car runs 10x better in colder weather when the coolant temp is around 170. Summer is coming, temps are going up, would a 160 or even a 170 thermostat really hurt??