I use stanadyne year round in my Jetta and cummins with good results. A friend who rebuilds injection pumps swears by it and I would agree. The micron rating has a lot to do with it but also the location of the filter and fuel line also have an effect on it. I used drive a feed truck that would freeze up if the fuel was not treated but the line and filter was hung on the outside of the frame rail beside the tank. The mechanic would come out and dump 911 in the filter and back in business.
