#2 ULSD: has maximum cloud points during the winter seasons based on the average temperatures. Based on some testing done winter, I've seen cloud points as low as -15F and as high as +24F, it depends on the geographical location and refinery supplying the terminal. To your point about the consensus of 32-34F, this is highly unlikely the waxes in diesel will start to cause issues. However, water's freeze point is 32F. And EVERY gallon of diesel fuel contains water. So treating at least when temps get down below 32F is going to help prevent water from freezing.
#1 ULSD: typically has a cloud point of -40F or below. At least in the areas that use #1 ULSD.
Telling you the temperature that off-road diesel will gel at is difficult without knowing what part of the country you are in. It is the exact same as #2 ULSD in all characteristics except for color so wouldn't matter if Clear or Dyed. But if you are able to give me a general area of the country, I could help determine the temperature issues could begin with/without an additive. Also, if you could provide if you are a farmer, O/O, have a fleet, etc., that would be great as well.
*Information explanation:
- Cloud Point: The temperature at which the waxes in diesel fuel will begin their crystallization process and the fuel will become visually 'cloudy.' In most cases, the higher the cloud point means the more waxes there are, the lower the cloud point, the lower the waxes. More wax in a diesel fuel typically means the more chance for winter issues unless properly treated with an additive.