I decided to add secondary fuel filtration on my Duramax as I felt from reading various tests that the stock fuel filter did not adequately clean the fuel on the stock 23,000psi fuel injection system. It has been tested that the OEM fuel filter on the Duramax is only slightly more than 44% efficient at filtering fuel down to 2 microns giving an ISO rating of only 16/14/11. This has been found to allow a sandblasting effect to happen on the inside of the injector causing its internal parts to prematurely fail. Therefore I decided to run a CAT fuel filter that is rated at 98% efficiency down to 2 microns giving an ISO rating of 14/12/9 which tests have shown to be below the target of 15/13/10 cleanliness standards for a 23,000psi system.

Caterpillar spent hundreds of thousands of dollars doing research on why their HEUI fuel systems were failing at an early/alarming rate. The results of their work indicated that it was the "hard particles" in the 5 to 10 micron range that was causing premature failure of pumps and injectors in their electronic, high pressure fuel systems. Current diesel fuel is unfiltered below 30 microns when it leaves the refinery. The diesel fuel continues to pick up contaminants with each transfer, each step of the way until it is finally deposited in its final underground cesspool before delivery to our Duramax engines. If you have not read the CAT research papers, I would highly suggest you review the work. Nowhere in their study are asphaltimes, slime, etc. mentioned relative to a cause of early injector/pump failures. Granted, these contaminants can be contributory to clogged fuel filters/shut down/problems. However, the 5 to 10 micron particulates has been singled out as "the" culprit in high wear rates by not only CAT/Southwest Research but is a textbook failure cause in high pressure hydraulic systems. In the CAT work, reducing the ISO grade by one single number doubled the life of the fuel injector/pump system.

There are many fuel filter options out there as well as fuel filter kits, the hardest part is deciding what you want to go with. I chose to install a kit from Nicktane.com that comes complete with everything you need to install, except the fuel line disconnect tool which can be purchased at any auto parts store. I installed this kit with a little over 11,000 miles on the truck.