Full is good
Leaving the tank full is good because there is less room for moisture to accumulate from air temperature changes in the tank. Moisture is biggest enemy of diesel fuel system. I don't know if Sta-bil does any good in diesel. I never used it but if it is labled for it, I guess it is o.k. BioGuard and similar products should be added regularly when adding fuel, not just at end of season. It prevents bacteria and fungal growth in any water that might be in the diesel. Also, check and/or replace fuel filters. The Racor type should be checked for water regularly. I am emphasizing water because it really is bad for diesel engines. Keep it out of the fuel and keep stuff from growing in it. I concur with changing of oil at the END of the season, as the manufacturers recommend. This is mainly because of the potential of moisture in the oil. This helps prevent corrosion of internal parts. Regards, John
