You have to realize that there are many refineries operating in or near the Rocky Mountains, we are one of them. Our distribution area has roughly a 1000 mile radius and ranges from sea level to 4000', in some cases even more. Some of our fuel even makes it up into the Arctic. There is a lot of thought, planning, historical data that goes into fuel deliveries, refining has been around for many years. Is it fool proof? Of course not, but like I said, we've never received any fuel back from retailers because it didn't meet requirements.If I only bought fuel nearby, yes it would be simpler. What I was trying to say is that the climate can change quite a bit within an hour or two of driving from here.
Getting fuel on the way home, in the fall or winter, 500 miles away is most likely not blended for here. And I don't expect it to be.
My reason for bringing up altitude was simply because it affects temperature. I can gain 20-35 degrees by driving SSW for an hour. And I often get fuel there.
To give you a much more extreme example, think of the conditions a long haul aircraft goes though. It could take off in LA at sea level at 95°F, travel over the north pole at 40 thousand feet and land in Siberia at -40°F. They burn what is essentially a light diesel that must meet very strict specifications. Highway fuel obviously isn't blended to meet the same specs as jet fuel, I'm just pointing out that refineries can very easily blend to very broad conditions.
Anyways, I think I've beat this to death. I say keep using the Howes, it has many other benefits other than anti-gelling properties.