Buying fuel in IN or IL is a bad idea in these extremes because they cut the fuel with a higher amount of bio which of course gels faster. If fueling there, you must increase the additive to compensate.
This isn't
necessarily true, though it's a reasonable bet. Mind you, I have been fueling up with diesel here in IL all through the coldest of the cold here (-18 and colder) and haven't had gelling issues. And, it clearly says on the pump that it is some percentage biodiesel.
But then, I'm using Stanadyne Performance Formula, which is to Power Service what an Atom Bomb is to a firecracker.
I expected to see a lot of gelled trucks on the road during that cold snap and I did not. Running all around Chicagoland each day, I never saw more than 2 trucks a day stalled on the road or shoulder.