downside to aftermaket racing thermostats your car will never get warm in the winter. My buddy matt has one on his CTR swaped EK Hatch. He hates it so much right now because on his 20 minute drive to work he dosnt get one bit of heat. He even starts his car 10 minutes before he leaves. Summertime I would say run a racing thermostat, but winter I would say run stock. Swap them if you know how to install a head and do your own timing. Its fairly easy.