Have any one seen a decrease in thier fuel mileage as the outdoor tep. has droped. Mine has went down by 4 mpg and is still going down as it gets colder and the clodest has been is 30f.

 

Winter mileage goes down on all vehicles. A combination of oxygenated fuel...more idling..stiffer lubricants because of lower temps...lower tire pressures if you haven't checked them since it got cold. Nothing new about that.

 

Mine hasn't dropped more than a couple of tenths. How much are you letting it sit and idle to warm up?

 

Mine has gone down perhaps 1-2 mpg vs. what I got under the same trip conditions in the middle of summer. Yesterday I made a trip (3 hours there, 3 hours back) at highway speed that I got 22-23 mpg in the summer (75 F) and yesterday at 30 F, I got 21.5 on this trip. I've driven this trip literally hundreds of times (not all in the EcoBoost, obviously, but just as an indicator of how familiar/stable the route and speeds are).

 

Mine has dropped 2 mpg so far. It's been in the mid 20's around here lately for lows, with colder weather coming next week. I expected this to happen, I'm still getting 16mpg avg with about 60/40 hwy city driving.

Better than the 11.5 I got last winter on a STOCK 04 FX4.

 

I have also seen a drop of about 2mpg. Temp has been in the 30s pretty regularly. On the flip side I have been letting it warm up a bit before taking off.....

 

I dropped about two mpg with my first tank of winter blend fuel. I also plug my truck in at night and that's made a difference. The engine heats up faster and doesn't dump as much gas running cold or idling.

 

Winter blend fuel.......