fiberglass tanks
Hello all: I have read quite a bit about this issue in various places. Actually, ethanol driven decomposition of fiberglass resins in these tanks may not take the form of particles trappable by fuel filters. Instead (or in addition) ethanol may actually dissolve some portion of the resin and allow it to pass any filter (its in solution) and wind up in the cylinders and be combusted. From what I have read, in a short time, solubilized fiberglass resins can ruin an engine. Its not only a pressure test thats required here; this is only for tank integrity at the time of the test, but a very close visual inspection (at least) of the tank interior to assess possible damage to the resin. In addition, I would take a sample of the contents and have it analyzed for resin or its components. That way, this would confirm whether resin that has gone into solution (which would indicate degradation of the tank), or not. I dont know if this is done routinely, but if it can be done, sounds like cheap insurance to me.