Buffalo said:
The emulsifying/demulsifying debate will probably go on forever. This is only my opinion but, it seems to me that if you had a storage tank with a drain at the bottom, a demulsifier would probably be the way to go. It would seperate the water and allow it to be drained off when needed. Since our trucks a bounced around a lot while driving it seems like the water would break up and suspend itself in the fuel until the truck is parked for quite awhile.
Maybe, breaking up the suspended water into very small particles, lubricating it and then sending it through the fuel delivery system (emulsifying)might be the way to go.
Joe F. (Buffalo)
You and Dieselminded have that right! Those that believe in Stanadyne and demulsification in vehicles are simply buying into their marketing and believing in the theory more than the reality. OEM and Aftermarket water separation only works on big slugs of free water. Ever wonder why there is never any water when you drain the fuel filter housing into a glass? Demulsifiers are great in static environments like a stationary tank with a bottom drain, but as vibration and motion are introduced as they are in a vehicle, their effectiveness is greatly reduced, as water does go back into suspension. It's a great concept in theory - to demulsify and have the water separator catch it, to stop water from ever passing through... it just doesn't work in reality for a few reasons. One because of what I said above, with the dynamic environment of a vehicle, and two because typical fuel does not have free water in it.
Guys, understand that all diesel fuel has water in it, typically 60-80ppm. Once that number gets around 115-120ppm, water will start to 'fall out' of suspension, and becomes 'free water'. Despite their claims, OEM and fancy aftermarket water separators do not filter out water smaller than 115ppm. I personally have verified this via laboratory testing on a variety of fuel filters, most noteably the OEM vw TDI separator/filter, and the Stanadyne Fuel Manager series of filters. We did before/after fuel analysis testing and the water was never substantially reduced (measured using Karl Fischer method), using Stanadyne's demulsifying additive for the test.
Therefore what folks need to do is decide if they want to use a fuel additive on a regular basis for the unlikely event of getting a bad tank full of free water, or if they want to use an additive that will make the small amounts of present water(less than 115ppm) safer to pass through, since it will do so inevitably. The reality is that additives only disperse their own volume of water (2oz additive only disperses 2oz water), so if you get a truly bad tank of water, the additives aren't gonna help either way, not to mention the fact that the separators typically will catch really large slugs of water.
There is a slight separation within the 'emulsifying' group of additives, between traditional emulsifiers and solubizers, but for the purpose of this discussion, we'll keep them together. The point is the same for the most part. Armed with the facts above, I run Redline and fill up at the same good quality fuel source every tank. Primrose, Redline, FPPF, and Power Service DFS are all in the 'emulsifying' group and work well.
Tschwab for the record Mercedes Benz endorses Redline fuel additive use, it's right in my E-class owner's manual.