FWIW, I've used a number of different brands of fuel additives and I don't think that some of them really raise the cetane as much as they claim to do.

I've occasionally purchased some sub-par fuel, engine would loudly cackle under accelleration and start hard. I've added brand X cetane booster with absolutely no improvement or difference.
The only improvement came when I filled up with a half tank of good fuel. Quieted the engine down in 30 seconds after starting.
Brand X additive didn't do squat.

Alan, you would probably know the answer to these questions- How many actual different refined brands of diesel are sold around here. What I mean is- How many different sources of diesel end up at all the different brands of stations? Do as few as one or three different refineries sell to all 10 or more local brands of fuel?

One reason I ask is that there is a big name brand station in SE Wyoming that I used to buy fuel at, and it was awful stuff, like I described above. There is the same brand of station on I-25 near Longmont, and I've never had a problem with their fuel. It can't be the same stuff.

And the last question- Do you know if and where I could buy straight #2 around here in the winter- not the 20%-30% kerosene winter blend.

Thanks.