Well I did a lot of experimenting last year with different fans (up to 5) and the taurus fan easily bested all of them. My flexalite controler went out 30337 I think. It was the best one with the adjustment **** and I was about 80 miles from home. I took a wire nut and my pocket knife (I keep extra parts everywhere in my car) and i wired it to the slower speed direct. On a 95 degree day on a two lane black top with a speed limit of 45-55 The temp ran halfway between 180 and 220. again it was wired direct so it ran all the time and got me home and out of a jam. I looked down and saw the needle going into the red and stopped and I could smell the controller so I did a quick fix and it worked. A two speed fan is like a insurance policy. I think my problem was the controler was not designed to handle 40 amps. Most do 30 but the taurus fan has to have at least a 40 or it will blow.