People don't realize that two tanks doesn't mean it's ready to go with alternative fuels. You start on a rear diesel tank, then switch to the front tank that has a thick blend, so now, the diesel left in the return lines is going to the front tank until everything in the system is the blended fuel. Then, when too switch back to diesel, you have your blend in all the return lines which gets returned to the diesel tank. Do this many times and it compounds to the point that you have an unwanted blend in your supposed diesel tank. I'd you climate gets cold, that can be a huge issue. Thicker fuels, whiteout proper heating, are very ******* an IP, not to mention, possibly shearing the Shaft in the IP of cold and thick enough. any savings is negated by the shortened life of an IP. an initial investment goes a long way.
Edit: even just getting a taller Donaldson fuel filter and filter head (which can be a coolant heated filter head) would allow for a taller filter wrap. I have a Donaldson filter mounted in front of and below the passenger side battery.