When I was a boater, I used to always read about larger yachts useing a diesel fuel polishing system. This kept the diesel fuel in tip top condition. I do not run generator on diesel but for those who do, it may be something for people with larger 1... Thousand liter fuel tanks to consider. I have her had a problem with my tractor diesel but that’s probably because I use it fast enough. A person wishing to store diesel just for generator backup may wish to explore polishing systems. Apparently it also makes changing of fuel filters easier.