On 2 micron vs 5 micron (factory)- the type of LP you run can have a major impact.
Unless you are spending around $200 per filter, you are not getting an ABSOLUTE rated filter. Meaning 100% of anything that size gets stopped. Almost all filters are rated as NOMINAL.
A filter rated “95% nominal 5 micron” means it catches 95% of everything larger than 5 microns. The rest goes through it to your ip, injectors, and whatever bypasses the injectors goes back to the tank.
The ‘bigboy’ LP systems have a direct feed that when more fuel gets pushed than the ip can process, there is an additional return hose that goes back to the tank. When talking the amount of fuel say the FASS system processes through its filters and the 6.5 rig is just normal driving, this makes A LOT of fuel just get recirculated back to the tank. And if the FASS filter is 5 micron nominal and so is the GM FFM, what’s the big deal?
You pump in 20 gallons of dirty fuel into your tank. And the GM LP/FFM gets it all once. Gets maybe 10% of it twice. (Kinda high estimate but for sake of argument let’s pretend it is that high). Gets maybe 1% of it a third time. Then it is time for you to fill up and add in 20 gallons of dirty fuel again.
You went from 5 dirt to 0.5 dirt to 0.05dirt…
FASS or Airdogg with their filter and that LP pushing massive quantities more through and your ip and injectors still see the same amount. But now the LP is shoving 10 times the amount of fuel through those annoyingly large filters. And they have to be that large to handle the volume of fuel going through or they would tear inside. What is happening to the fuel is: 5% of the 5 microns gets through, 0.5, 0.05, 0.005, 0.0005, 0.00005, 0.000005, 0.0000005, 0.00000005, 0,000000005
Now you finally go buy that next 20 gallons of dirty fuel.
Running the nicer LP that has ample flow and pressure to keep the ip happy is one part of the equation. And while my example above isn’t exactly accurate it should show you why diesels that run these systems have so much less problems than ones with just enough to not break down too often systems- aka get you through warranty systems.
I know fuel engineers who go to the gas stations and pump fuel into bed mounted transfer tanks. Then drive home and pump it from that tank into barrels in the garage where it gets ran through the big annoying filters for a day, back and forth between two barrels. One guy has timer on his to auto shut off. Another just lets it run until the next day when he turns it off himself. Then they pump that “polished” fuel into their trucks. Neither of those guys live here in Vegas. We don’t have humidity, so almost no rust in the gas station tanks. But when they moved to humid areas of the country they invested. They also run the big boy LP on their trucks for insurance.
Over the top? Check.
Use the filters for tracking information at their jobs? Check.
Get high miles from their fuel systems in their trucks? Check. —
Over 700k in a 01 dmax for one guy- original injectors…hmm.
So what does better- two passes at 2 micron, or 20 passes at 5 micron?
There is a reason I keep telling people invest in the big boy stuff.
I have db2. They are a dime a dozen. On my 6.5 pickups I have ran straight used motor oil. When the smoking got bad, it was time to pour water into the intake and remove carbon. When the ip and injectors were cooked (hard hot starts) I just spent a few hours and $75-100 for a used ip. I rebuilt the injectors ahead of time and slapped them all in. Now abuse it some more. The db2 went in the scrap bin and who cares because there is millions more to be had for next to no cost.
There is extremes on both ends.
You gotta figure what investment is worth it to you. The expense of a ds4, the added nonsense of what it takes replacing one (komputer/timing), hard to get parts to rebuild injectors now, etc- I just don’t understand how not having these set ups on the truck is near standard now. This simply wasn’t an option back in the day. But we also didn’t have to fight some evil villain nonsense like algae that can live inside of fuel. Our fuel was a lubricant, it didn’t need lubricant added to it.
I am “chicken little”. I over build. I rather not do something than do it half way anymore. Take this into account when considering my opinions. But because I’ve done enough to learn all that I have, consider my opinion is all I say.
If you have the money to let your truck blow up on a Tuesday and your Wednesday can continue as planned - the roi might not be there for you. If your world comes to a halt on that Tuesday afternoon to the point you will loose sleep that night wondering what to do tomorrow…
