Hi all, Worked on cars most of my relatively short life- had mostly honda's and mazda's, etc. Now have the lexus and LC and both have the viscous fan clutch, which is new to me.... I guess my question is: why are these used and is that viscous coupling a temperature controlled clutch, like the fancy diff, etc..? Or is it just a buffer to help smooth the engine speed differences? We all see the fan turn at start up on a cold engine, so, what's the point? don't think this has been discussed? thanks.