Review on Hayden Automotive Premium Fan Clutch 2917 by Kevin Witherspoon

I bought it as a replacement while I was adjusting the timing. I found the original hard. The new block feels stiffer than the old one, but smoother. I was thinking about upgrading Fan E, so I turned the fan off completely to take advantage of the cold weather. The engine is noticeably quieter without the fan, but my gas mileage (using the Scan Gauge II) hasn't changed, and I could say 17-18mpg on a mixed highway driving a 2006 F150 5.4L. This tells me that the "clutch" action of this unit works better than I thought and limits the stress on the engine in such cold temperatures when not much extra airflow is needed.