Fuel Air Separation Systems
 

Does anyone here own a diesel vehicle? I am just wondering if you guys have an experience with fuel separation systems like Fass Fuel? What are its benefits?

FASS and its direct competition (Dad's company) Airdog are both systems that remove dissolved air from the fuel lines (among other things) before it reaches the injection pump in diesel engines. The benefits include:

Increased fuel pressure
Improvement in fuel economy
More power under load
Longer injector lifespan
Increased consistency of the above
Peace of mind

Drawbacks include:

Not factory tested
Maybe waste of money
Not maintenance free
Improvement not drastic

In the end, the decision is yours. Many fleet owner operator drivers swear by them, providing endless mountains of examples. Many claim the return on investment is a year or less due to fuel economy alone.

The naysayers argue that the stock filter system is sufficient and the extra device increases risk of failure. As with most aftermarket parts, they do not increase your warranty coverage or get a seal of approval. Without medical device or SAE testing, the benefits may not exist.

Here is my take on the subject: If you've ever had the pleasure of filling up with bad or watery fuel, this rig would definitely save some grief and maybe lots of money. Not to mention downtime in the road somewhere. A lot depends on the condition of the vehicle it will be installed in. If the stock setup has problems with sucking air or water, it can only help. Proper installation is key.

The early common rail Cummins engines in the Dodge pickups were notoriously sensitive to water in the fuel. I think this was mostly the result of inadequate filtering and water separation. I don't recall any commercial trucks with this engine having the same issues. Dodge was saving a few bucks per vehicle that ultimately cost owners thousands. Thus the perceived need for these aftermarket systems.

I bought a 1995 Dodge Cummins and was quite surprised to find it didn't have a water separator, thinking this was standard equipment on any diesel. Adding one, however, costs less than $50.

A fleet manager once told me diesel fuel can have 5% entrained air from agitation alone. If you've ever had an air bubble in your injector circuit you know how this can affect performance. So there is some merit to the claims made by Fass and Airdog regarding air.

Personally, I don't do business with companies that use the word BILLET in their literature or build websites that look like video games. And these $600 devices do break down which is why owners swear at them as much as by them.