That's how I was thinking till I said fuck it and ordered the cheapper one and let's said I have bought. 4 more for others and have one on my radiator that runs none stop when car is on and never goes near halfheat.and one on my ac cond...when I tested it out the box and it jerked out my hand from the tq and rpms and then blow my shirt around lik I was in a tornado I was sold I have had the rad one sinse march 2008 and it comes on none stop when the car is on never messed up so I'm happy