This morning I got an answer from my local Sunoco service station. I had asked what type of diesel were they selling, type 1, 2, 4 or 6?
Today the manager told me "type 2"
My reply "wrong answer, that's summer blend. I'm not going to buy diesel from here any more this winter."
This excerpt may explain it better -
"#2 diesel fuel has a wax component that contributes to the lubricity and heat value of the fuel. The "cloud point" refers to the temperature when the wax precipitates out of the fuel in the form of small wax crystals. Different fuel blends can have very different cloud point temperatures, generally ranging from -10F to +40F. #1 diesel fuel does not contain large amounts of wax, and therefore does not have a noticeable cloud point. Diesel fuel distributors blend local diesel fuel supplies so that the cloud point is usually not reached. However, if ambient temperatures fall below the cloud point of the fuel on a vehicle, the precipitated wax crystals can quickly coat and plug a filter element."