As a Master Tech, I have to take a lot of classes every year to stay up with new developments, and in one class I was shocked to find out a new problem with the new ULSD(ultra low sulpher diesel). It seems that since our industry standard fuel that is now mandated by the EPA, has been rotting out fuel tanks and damaging injection systems. The extra step it takes to pull out the sulpher uses a salt solution. They found out that after the sulpher extraction, if you leave the salt solution in the fuel, it rduces Nox emmisions- dramaticly-well now it has been found that it corrodes the fuel tanks below the fuel line and companies like Navistar have put out a service bulletin stating that all trucks running USLD should have thier tanks cleaned out once a year. Also, the sulpher helped keep microbes from forming in the tanks-since the sulphers are out, there are lots of "critters" living and forming sludge which helps to plug filters. Just because it's a cleaner fuel, it isn't better. Ever since E85 came into the mainstream, many sources have said ethanol is corrosive. The Ethanol itself isn't, but the water it attracts is. If it is stored and handled corroctly, it don't hurt anything, and I have never heard of an E85 fueled vehicle with a rotted gas tank. I will try to get the service bulletin for this diesel fuel problem and post it.