Winter & OIl

Now that winter is upon us I was thinking what the effects of the cold weather play on suspension oil. We are told is to run 5wt in winter and 10wt in the summer in our cars. This is because oil thickens in cold temp. It seems to me that this could come into play as far as dampening, setting oil height, ect. in my mind this might possibally have a noticeable effect. At what temps does oil start to thicken and thin. Does operating temp reach the same being 80 degrees versis 40 degrees.What led me to this topic was, I have'nt got my furnace hook up yet, and I was doing a service and noticed the oil was noticeabley thicker.(I no get heat!)

thanks russ