I usually run my F250 diesel with the hubs locked in whether the roads are bad or not, mainly because I frequently get into places where I need 4wd. I do unlock them for extended highway use if they are clear and dry. That truck is very nose heavy so it has trouble on the slick stuff. My 96 F150 gets around in the snow pretty good in 2wd, if it gets nasty I lock it in. The hubs stay locked in on this one unless the roads are clear and dry.

 

I like to run Low 2wd some times when I want to pull wheelies...