Oh man when this letter arrived in my mailbox I was pissed. Not only did I just spend over $5000 on repairs related to the failure of my EGR cooler, proper Nitrate levels?? *** Ford!!!!
I have used the test strips, almost 3 months prior to my failure I used one and all the levels were fine. Basically low levels happen when you don't use the proper mixture; 50/50, or never change your coolant. I always follow my recommended schedule (give or take a few thousand) and my truck has had tons of problems.
Ford needed to do some better R&D

(F ailed O n R esearch & D evelopment)

instead of reminding customers of proper maintenance schedules. I understand part failures do happen but looking at this site and others about Turbo, injector, oil cooler and egr cooler failures really makes you wonder if not checking the coolant every interval really makes a difference.
Still, I guess oil changes and proper coolant maintenance are important, to ANY vehicle.
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2005

250SC FX4 6.0L 3.73's, '03 Turbo "Whistler", '07 turbo drain tube, AFE PRO Stage 3, Edge Insight; MBRP Turbo back cool duals, cat delete, SCT X3 Programmer with my custom tune, CFM Inlet, egr cooler delete, billet egr delete, coolant filter, Boss 8' Pro Poly, Wheelen hide-a-way strobes, Sho-me LED's.