> Do I need to put some additive into my diesel truck tank if the
> temperature will get to 10 or 15 below (maybe)?
If you are buying fuel regularly then the local stations will have switched
over to winter fuel already. So it is not a problem.
I remember in the mid fifties when my uncle had to do help a truck. They
had bought fuel somewhere in the south and by the time they made it to
northern Missouri we were in a sudden early cold smap and the fuel had
gelled. I remember it was a big problem getting the truck warmed up enough
to get fuel flowing to flush it out. We were one of the first in the area
with a Diesel tractor and my uncle used Diesel crawlers and I remember lots
of problems with gelled fuel. Those days are passed.