IT WILL OPEN SOONER AND BEGIN TO COOL SOONER THAN A 180 STAT, THUS IN THERY KEEPING THE ENGINE COOLer for cooler intake air temps and lets the computer keep adding fuel and not retrding timing , on a hot day though, the truck will still run warmer than 160 , but the stat trys to keep it cooler. you wont feel a big diff stock, but it will work good if your tuned for it, id say 90% of the time my truck runs cool except for the really hot days it still sees 210