I use a 160 stat and I run from 170 to about 185 on the highway on very hot day. What I did not like was stuck in traffic it would creep up to 200 and I dont have a shroud right now. So I decided to try this electic fan along with my stock fan and it did the trick. I have it on a toggle switch and I only turn it on when stuck in traffic and it brings it right back down to 180. Ron