Re: Diesel additives for the winter
Well, you might want to do some Googliing on "diesel gel temperature" or "winterized diesel" or other related topics. You will get varying opinions, but the preailing view seems to be that the modern Ultra Low Sulfur diesel gels at a much higher temperature than the high sulfur or low sulfur stuff that was prevalent 30 years ago when I was a trucker. I drove day trips in Iowa where sub 0? fF temps were a possibility throughout the winter and sub-20? could be fairly frequent in January. We refueled at the terminal and used a blend of about 50-50 #1 to #2 when the temps were likely to drop below 20? F. That wasn't always enough when it got really cold.
I haven't used any diesels since the early '80s, so I did some research and found out that the Ultra Low Sulfur (ULS) in use for the last 10-12 years or so has a much higher gel temperature than the stuff I was using in 1980. It can gel in the range of 20? to 25? so it's right in your ballpark. It can actually be a bigger problem in vehicles (or tractors) that sit for several days between uses. Remember, once it gels, your pretty much FUBAR until the ambient temperature rises well above the gel temp i.e., 45 to 50 degrees.
I would use an anti-gel additive in the tractors, make sure it gets mixed well and run the engine long enough to be sure the anti-gel has gotten to the injectors. It may not matter, but you really don't want to find out when it does.
Just too add, I wouldn't bother treating the 275 gal storage tank, just the fuel tanks on the tractors. In your borderline situation, that should be enough.
