I never saw 40 below but certainly single digits...
i guess if i were gonna store a car or truck (gas or diesel)
for more than 6months id consider....
Gasoline...id COMPLETELY fill the tank & dump in plenty of
staybil or something like it...id run the engine/drive it and get
some of that staybil thru the lines, carb & injectors...
id change the oil, lube all the joints i could, put the car/truck
up on blocks (get the tires off the ground)...and then id shut
everything down (pull the battery & put it inside) and id squirt
some oil down on top of the pistons...not much just enough to keep
things from rusting & sticking...typically a teaspoon is all you need.
diesel id do all of the above but id throw some anti alge fuel conditioner
in it...specific for diesels and something that does NOT have
alcohol in it..and id fill up the tank as far as possible (full tanks
allow little if any room for moisture)
if youre talking LONG term storage then id consider empty-ing out
the tanks and fuel lines as well as draining the block & radiator....