Mine engages even when I don't think it should. Pulling hills towing heavy I have seen 220-231 degrees frequently. It gets annoying on a long trip listening to the fan clutch when it engages at 3500 rpm every 30 seconds. /ubbthreads/images/graemlins/eek.gif I can see it coming on then, but mine even comes on at 205 degrees empty in hot weather. I might need to have it checked.