In my second year of my first ever diesel truck (2021 GMC 2500). The weather conditions this past weekend provided me with another great learning experience. At the last minute last week, we decided to take the truck to Tennessee to be with the kids for Christmas. At the low extreme, the temperature reached 3 degrees one day while we were there. It was a little disconcerting when we went out and the truck would not start. It took a little while Googling to come to the belief that the diesel fuel had gelled, or at least reached a viscosity point where it couldn't pass through the filter. It appears that I should have started using additives as the weather started turning colder, and especially, since I was heading north out of south Louisiana. My question to those with long diesel engine experience is, what diesel additive do you use or recommend for winter use?