I finally was able to borrow new FFH and this is what I learned. Like the CMAX you gain about 3MPG with the Grill Covers. Water temp went from 177deg.F to 207deg.F right in the center of the operating temp for ICE(202-212 according to FORD). Outside temp was 35degF. I would like to do more testing but dealers don't want to put any miles on their cars. My test route on fwy was 14.4mi according to odometer but the GPS had 14.7mi which means you FFH owners are getting 2% better MPG's than you think you are. That could be as much as 1MPG. A step in the right direction.