tditom said:
I'm not trying to scare anybody into doing anything. i am sharing my concern, which has caused me to take precautions. people can take it or leave it, but they need to do so knowing the facts.
Unfortunately, you have little in the way of facts, or scientific logic, to back up your cautious behavior. I am merely pointing out the paucity of information, including from the pump manufacturers. You may be satisfied with what data is available, I am not.
Ironically, we seem to trust the fuel manufacturers enough to put their fuel into our cars, but somehow we cannot trust how much additive they use. I would recommend using a major supplier for diesel, since they have the most at stake and will more than likely overdo their use of additives to protect their market share. Fleet owners of expensive diesel machinery may have quite an influence on their livelihood should pump failures begin to occur. I personally don't trust some suppliers over others and feel that the major oil companies have more resources to taylor their additive package to the available fuel.
Somehow, aftermarket additives seem to have no "side effects" with daily preventive use. Historically, there have been cases of adverse effects with certain additives to fuel or oil. This is why most car manufacturers routinely recommend against them except for specific purposes like fuel gelling etc. You even acknowledged that in one "study" the most popular additive of all actually decreased lubricity. This point was also in one of my posts.
I agree with others that find this issue relatively unimportant, especially with the idea that a compromise was established. It annoys me how authoritative some seem to be, however, in claiming it to be unwise to not use aftermarket additive with every fill. Somehow the additive makers get more credit than the car manufacturers and fuel suppliers - why trust one group over another - they all have a financial stake, and the additive makers want you to believe their magic elixirs are better than sliced bread! Car manufacturers tend to be very cautious with issues such as engine oil specs etc. and are known to change recommendations retroactively if they find a problem. Even GM recommends specific brands of gasoline due to their quality. So if you base your mistrust on past behaviors, I would tend to trust Mercedes if not VW for proper advice over some guy on the Internet or some snake oil sales pitch.
My 2002 NB TDI went 156,000 miles and its fuel pump (and rest of the motor) was working perfectly when I sold it. No additives either. No fouling of intake and only 2 glow plugs needed to be replaced the entire time. The CDI made that wonderful car sit in the driveway.
TM