Foaming diesel is a puzzle to me. When filling my 2006 f350 it takes forever to get a full tank. If I don't allow the foam to dissolve I miss about 4 to 5 gal from filling my tank. I have pumped thous...
The fuel is getting aerated by the path it's taking to the tank. We've got a couple of diesel tractors where the front filler neck is molded to go around the operator platform and takes a weird shape to get to the main part of the tank. Like you the last 5-10 gallons is tedious as the fill neck area fills with foam. The other tractors that have short filler necks that lead directly into the main tank don't foam at all.