My buddies 2015 just popped up last week so he called me. Went over and showed him what to do with my strips, log it etc. His wife told mine he should have taken it to the dealer, didn't trust me I guess and he's an engineer. In 2016 they are hopefully getting it right but in 2011 it was still 6.4 strips.
Show his wife this post then - on my 2012 I took it to the dealer to have the additive checked. Took a single strip, put one end of it in the main catchment tank, held it up to the bottle's color code set and said all OK. No test of the secondary tank; no letting the unit cool, nada that the guide says to do. For that I was charged 30 minutes shop time and $10.00 for the test strip. So far no message on my 2015 but I hope who ever checks them now knows what to do by the book.
Why ask the forum: Part of the issue is time - Google is a savior many times a day in my current job as a computer geek. So much going on that no one can really be an expert in all of it (at least IMHO). that said, you can read so much and get various ideas and methods but ultimately it comes down to which one works. Here on the forum we have expertise from true experts who work in the field of Ford automotives every day, plus the literally thousands who work on these trucks for their personal pleasure. Why not ask those who do, and have done it, before for their expertise. Might learn a shorter way, a better way, and an effective way to do what you need to do.
Personally I'd like to thank everyone who has ever helped me on the web's various forums. I hope that I can repay the kindness to others in the future (pass it forward.)
Apparently a line I tried to move just plain dropped out of my post above, and now 'Edit' won't work. So, anyway, the portion missing is: ...comes down to which one works. On my vehicles the first stop is the manual but I often find that either the description is too cryptic for my old brain, or worse yet, so limited as to be worthless. Here on the forum...
OK, new update. Notice to check coolant additive came up on my truck last Wednesday night. Took my 2015 F450 to Salina dealer to do test; did a single test, again, using the reservoir coolant. Strange thing is that the local Ford dealer told me no need - given that I only have a little over 14000 miles on my truck. Regardless, had to go to Salina for something else and stopped by the dealer there just because it was there. That service tech told me not only don't ignore it (ie. have it done), if something did go wrong Ford MIGHT use that skipping of maintenance against me. SO, $42.00 later I was checked, everything was OK but I feel that is very cheap insurance given what we read about Fords actions on some other coolant/cooling system items. What's that expression - easypeezy.
Again, I want to express my Thanks to all on this and other forums. Your knowledge allows us to get better usage of our vehicles!!!