Our local Ford dealers don't sell the test strips but I have been able to get them from the local International dealer, probably half price of Ford if they did sell them. Be careful not to add to much additive since this is very hard on the water pump. JMO

 

OK here is the deal...I should really save this to a text file so I don't have to keep typing it out over and over...

NAPA/Wix/Penray/Nalcool/Detroit Diesel/Ford FW15/Cummins-Fleetguard DCA2 is nitrite only formulation, and it uses a lot more nitrite than the other one combined (you'll see what I mean). It was the first developed by Detroit Diesel and Penray to combat cavitation which they had discovered when diesel engine HP began to climb. That is what the NAPA strips test for and that is what I use. The whole package is phosphate free with a borate pH buffer in it.

Ford FW16 or VC8/Cummins-Fleetguard DCA4 is a nitrite-molybdate mix. Fleetguard claims that they can get by with less of both (see above) because the two chemicals have a "synergistic" effect on each other (the whole of the mix being greater than the sum of the two parts). It came along later and was developed by Cummins/Fleetguard to deal with problems they had apparently had with the higher level of nitrite dropping out and depositing itself. The test strips have a pad for nitrite and one for molybdate and you line them up on a chart to get your protection level. These strips also work for nitrite only because the molybdate will be zero so you just use the first column. This inhibitor package uses phosphate as its pH buffer. I do not use it because I have engines that specify a phosphate free coolant. I do have Cummins engines. However, they come in a Freightliner chassis and Freightliner uses the nitrite only formulation, rather than this one.

There probably isn't much difference, however I choose to use nitrite-only. I have never heard of a problem attributed to using one over the other.

Birken