Found this link that gives a good explanation
http://www.uidaho.edu/bioenergy/Bioshortcourse/Diesel_Fuel_Props.htm
Here is the copy without the diagrams of the test apparatus.
Cloud Point - The cloud point is the temperature at which a cloud of wax crystals first appears in a fuel sample that is cooled under conditions described by ASTM D2500. The cloud point is determined by visually inspecting for a haze in the normally clear fuel. The apparatus used for this test (and the pour point) is shown in Figure 1.
Pour Point - The pour point is the lowest temperature at which movement of the fuel sample can be determined when the sample container is tilted. The apparatus used is the same as for the Cloud Point and is shown in Figure 1. The sample must be cooled following the procedure described in ASTM D97. At every 3oC of cooling, the sample is inspected and when no movement is detected after 5 seconds, the test is stopped. 3oC is added to the temperature where no movement was observed and this is the pour point. Pour points are always expressed in multiples of 3oC.
Pour Point - The pour point is the lowest temperature at which movement of the fuel sample can be determined when the sample container is tilted. The apparatus used is the same as for the Cloud Point and is shown in Figure 1. The sample must be cooled following the procedure described in ASTM D97. At every 3oC of cooling, the sample is inspected and when no movement is detected after 5 seconds, the test is stopped. 3oC is added to the temperature where no movement was observed and this is the pour point. Pour points are always expressed in multiples of 3oC.
The cloud point is the highest temperature used for characterizing cold flow and the pour point is the lowest. The LTFT and CFPP temperatures will usually be somewhere between the cloud and pour points.
When diesel fuels from petroleum or biodiesel start to solidify, they initially form microscopic crystals. If allowed to agglomerate, these crystals will grow large enough where they can plug fuel filters and fuel lines. Anti-gelling additives can be used to disrupt the agglomeration process.
Pour point depressants - Most pour point depressants, also known as cold flow improvers, work on similar principles. As the fuel sample is cooled, small wax crystals form. The temperature at which this occurs is the cloud point. As the sample is cooled further, the crystals agglomerate and grow in size until the entire sample solidifies. Most pour point depressants do not alter the initial formation of the crystals and thus they do not generally affect the cloud point. Rather, they inhibit the crystals from combining and growing to a size large enough to plug filters. The additives are generally waxes that are used in small amounts. They surround the small crystals and provide a barrier to agglomeration.
While pour point depressants can lower the allowable operating temperature of the fuel, the most common remedy is to blend #1 and #2 diesel fuel together. Number 1 diesel fuel can generally operate below –40 C (-40° F) without crystallization. So-called "winter blends" of #1 and #2 are used in the northern United States to provide low temperature operability.
ASTM D 975 does not specify a specific value for the cold flow requirements of diesel fuel. Instead, it suggests that one measure of cold flow, the cloud point, which is described below, be no more than 6°C higher than the 10th percentile minimum ambient temperature for the month the fuel will be used. The 10th percentile temperature corresponds to the minimum temperature that would be reached no more than 3 days out of 30 for the month. Figure 4 shows the values of 10th percentile temperatures during the month of January. ASTM D 975 contains similar maps for other low temperature months in the United States.
Biodiesel will generally start to gel at higher temperatures than #2 diesel fuel. Soybean oil-based biodiesel will form crystals at about 0°C and biodiesel from greases and animal fats can form crystals at 20°C or even higher. Low quality biodiesel produced with an incomplete reaction can behave in a similar manner as the mono- and diglycerides crystallize even at high temperatures. Partially reacted monoglycerides containing saturated fatty acids have high melting points and very low solubility in methyl esters. These compounds can fill fuel filters with a creamy deposit. The user may think the fuel was made from a feedstock that provides a high cloud point when in fact the problem is with the completeness of the reaction.
Attention: TDR Forum Junkies 
In other words, is there a reference pour point number that I can base or at least relate the Stanadyne claim to before worrying about switching fuels. My problem is I only drive the truck on weekends so A tank lasts 4 to 6 weeks.
