Terrible advise. This is Relic "knowledge" from the 70's, and needs to die. Factory recommendation is 5w20, the 5 is winter viscosity and 20 is warm temp. These oils lose viscosity the colder they get so going to a 0 is exactly the wrong decision. You do not need to play with this, going to a 0 cold viscosity is going to put unnecessary wear on bearings, especially when your talking about someone who is starting their truck "10-20 times per day". Its also a good way to lower oil pressure in a system that's already heavily taxed. Going to a 30 hot viscosity will do nothing but put extra strain on the oil pump and reduce fuel economy. You do not know better than the ford engineers who set the engine clearances and specified the bearings and oil weight, and whom actually have an understanding of the chemistry of modern oils.