It would appear that FORD built the cooling system for worst case scenario and they didn't have the money to do a perfect job. It would seem most people over think the overheating problem, because the ICE Smart Gauge will tell you if there is a problem. I have been driving for 2 years with the Grill Covers on all time with no problems. Plus there is a temp gauge in MyView if that will make you feel better, as I have said before the only time you need to remove the lower cover is on long uphill climbs. The Middle stays on all the time. For you I would close off all Grill openings to conserve heat. I don't know how far you are driving for each trip you make, but Grill Covers and Oil Pan Heater(if can plug it in) make a big difference during the Winter. I'm currently installing FORD ICE block Heater to improve MPG's more. IMO
I don't think it had to do with money. In most North American uses, there is far more chance of problems due to overheating than by being too cold. The problem with an ICE is always that it generates heat; Ford designed the system to keep the engine components within their desired operating temperature. They did not design for extreme climates, and they were willing to accept slightly lower MPG in order to make absolutely sure the mechanical components are kept cool. They have to warrant the engine...
That is not to say that a warranty claim would be denied because of grill covers, unless there was clear evidence of heat damage. I wouldn't use them myself (not that I need it here in SoCal), but I don't think it would cause a problem - if monitored closely. And that is the issue. Ford isn't going to design a system that the owner has to watch like a hawk to keep the engine within optimum longevity ranges. I realize that folks on this forum are careful, but not everyone is, and the car has to be designed to be idiot proof, especially with the number of lawsuits these days.
Edited by stevedebi, 05 November 2014 - 01:02 PM.