My cooling fans don't turn on untill a little bit below the 220 mark. While the motor appears to run fine @ this temp, I don't know that it's the ideal range. I've found that when the temp gets up that high, the heat robs the engine of power. For good pickup and power, the car performs best in the 160-190 range. Plus for the coolant mixture that I use, 220 is only 15-20 degrees below the boiling point. When a cooling system failure occurs there is not a safe enough "buffer zone" to give me enough time to pull the car over to the side of the road before the radiator cap blows. (ie: if while in heavy traffic the cooling fans didn't turn on because of a blown fuse, I could pull over to cool the engine down while I replaced the fuse. And then continue down the road. But if the coolant boils over before I can pull over, I'm then stranded no matter what because I've dumped the majority of my water out.) As for the the otterstat, the unit is sealed so you can't adjust it to have the fans kick on @ different temps. -Robert vin 6585 --- In dmcnews@xxxxxxxxxxx, joelpash@xxxx wrote: > Is 220 when the needle is right in the middle? If I remember > correctly, this is where it is supposed to run. The engine is > designed to run hot. It is possible to set the fans to come on at a > lower temp, but then the fans will not last as long.