You guys may think you're doing yourselves a favor money wise by using powerservice because it appears cheap, and is available at wal-mart. However, powerservice is 77% #2 diesel fuel. Ever wonder why you have to dose so many more ounces compared to stanadyne? Stanadyne's base is a lube oil, not diesel fuel... and is more concentrated. The cost per treated gallon works out to be cheaper using stanadyne. I also have noticed no difference in performance or mpg using PS, and during very cold weather(under 20F) I have noticed the stanadyne makes startups smoother and quieter.
All diesel fuel contains some amount of water. I've done 4 fuel analyses on different stations, and all have between 70-100 ppm water per gal. The big question is how do you choose to deal with it? There are two schools of thought. To EMULSIFY or DEMULSIFY, that is the question. Some folks truly believe that their water separators are as effective as advertised. If this is the case, use a demulsifier, and the free water that is separated should be collected. However, fuel testing before and after the filter has shown clearly that they are not anywhere near 90+% effective as they would like us to believe, in removing water. Vibrations (especially diesels) cause water in fuel to become emulsified/suspended in the fuel. While the separator may stop some, it's certainly not stopping all. A simple test to prove this is, pour some diesel in a glass, and a bit of water GENTLY. You will see the water settle to the bottom. NOw shake it... you'll see the water mix up into little droplets etc. This leads us to the logical step of emulsifying. Emulsifying additives cause all water to be kept in emulsion, and in very very tiny droplets... so small that they effectively pass right through the fuel filter, and the whole engine without doing damage. It's your call.
Primrose makes about the best emulsifying additive. They just recently started selling to the public, after providing 90+% of the US military's diesel fuel additives for the last 10 years. They are pretty short on marketing etc, as they generally deal with government sources, but the stuff is great. Highly potent cetane booster, lubricity additive, and emulsifier. Extremely concentrated, one 12 ounce bottle treats 187 gallons, and the price is cheap. That works out to just 2. 7 cents per treated gallon
I personally have used primrose powermaster 405 (409 for winter) for the last year with great results. Also a lab and lubrication engineer that I correspond with has tested before and after primrose treatment on an (expensive) cetane engine, and showed a gain of 5. 2 cetane with the listed treatment ratio.
Most people are happy with whatever additive they use because it's not often one gets a tank with large amounts of water. For the most part, fuel with water ppm under 130-140ppm will stay in suspension. If you DO happen to get that bad tank, or are vandalized... . it's your call... . I prefer to know that no matter what, the water in my tank will stay emulsified... . also don't like the idea of a pool of water at the bottom of my tank with a demulsifying additive.
That was a lot of typing, I hope you guys appreciate it, LOL~!
Attention: TDR Forum Junkies 
If anyone wants to email me, I'll send you copies of the 4 fuel analysis reports I've done on my local stations. Results are mindblowing. Myths broken. The old school thought of 'its a busy station, or a truck stop, it must have good fuel' is so far from the truth it's ridiculous... and I have the numbers to prove it. So folks, go on filling up blindly if you like. . and take your chances..... hey, they're only lift pumps and injectors right? This becomes 10 times more critical with 3rd gen engines than EVER before. The higher the pressure of the injection system, the more damage it stands to take due to contaminants, particulates, and water.
