Originally Posted by paddo

FYI:


It has been a few more weeks and there is no longer any indication of filter blockage, suggesting the growth has gone from my tank.

The reason Mercedes once recommended to add gasoline in winter if necessary, was for better starting. The reason for changing that recommendation was the risk of explosion. Pure gasoline's partial pressure creates a gas/air mixture that is too high in gasoline to be explosive. A certain range of ratios of gasoline will create an explosive level of gas:air, but I don't know what that ratio range is. It's a good point that a lot of modern gasoline has ethanol and I hadn't heard of ethanol damaging injectors before. I'm not sure if ethanol is added in PA / Jersey.

As far as the tank growth goes, it seems clear that it is not a problem for gasoline fueled vehicles. Clearly the growth can't feed on pure gasoline. The question is what minimum ratio of gas:diesel is required to kill the growth. My recent experience seems to suggest that the amount I added was very effective but I'd like to see a few more experiments with this. OF course if you have information that refutes this, I'd be interested to see hear back.

It does seem that due to the possible ethanol issue, it would be better to avoid adding gas all winter, and is unnecessary anyway. However I don't believe that a tank of 10% gasoline no more than every 2 or 3 years (when there is water accumulation leading to growth) will cause significant reduction of injector life. It may be that kerosene is similarly microcidal although I doubt it since it is much more similar to diesel fuel and a lot more pure. But if it is, that would be the perfect solution. I saw Kero the other day for sale, cheaper than diesel! Next time if ever, I have a grawth problem, I'll try a kerosene treatment. There may be forum members who run kerosene mix here, who can report on whether they have ever had a growth problem.

The other dilemma is whether to add any of the expensive tank cleaner I bought to emulsify the water. A previous poster advised that this emulsified water is just as harmful to the fuel system as unemulsified. Possibly it separates out quickly as it is heated on the way to the injectors, which would be harmful of course. so I'm not sure what to do, I think I'll just keep driving for now since the problem seems to have been solved.