Three tanks of gas ago (about 5 weeks) I got 36+MPG. It was my first 36+ tank, but the ones before it had been steadily increasing. I then used a certain brand of gasoline, and my mileage dropped to 32. Once that tank was gone I went back to "the good stuff" hoping to get my mileage back where it belonged. Well, my mileage dropped further and the last tank was 29.2MPG! Even my first tank was better than that. We hit a cold spell with temps in the mornings in the low 40s and highs in the 50s; is that small a temperature change responsible for this drop? If so, I'll have serious problems come December when temperatures are routinely below zero.
I can't think of anything else that could have caused the drop-off in mileage. I used all the tools I normally use to increase fuel economy; unless that one tank of gas ruined things for me (and it's from a national brand, so if it did this to me is it hurting others' fuel economy?), in which case I'll be very mad.
Also, as I know this might be asked, I pumped as much gas into it this time as I could and in fact had a little spill out. I only got 12 gallons in despite being very close to 50MTE.

 

are you using the defroster, I know here where i am the mpg has been really low during the summer because we have been using the a/c most of the time, I have been getting average of about 27mpg this summer, not as good as i was hoping for but then again its better than 14mpg i was getting in my truck.i guess i will only get good milege during spring and fall.

 

Actually, I've barely had the heat or AC on. I rarely have the vents on, just slight window cracking.

 

What is your trip time and have you noticed how long it takes to get to ev when cold?

 

queenfan -

I'm not sure that it was the cold as I'm in Hastings running my TCH and my mileage is slowly going UP even with the cold snap last week. Did your trips shorten up?

Scott

 

Another option would be if they are already delivering the winter blend fuel to the stations that have something like 10% MTBE or Ethanol blend there in MN. It is my understanding, cleaner emissions but less MPG.

 

Trips are always the same: 22.5 miles into work and 23.5 home (I take a different route to avoid traffic--the practice freeway for you, cast and blast). A little putting around on the weekends. It didn't seem to take any longer to warm up than usual. I'm well past the break in period and my mileage did jump (a very little) when I hit 5000 miles. I'm currently at 6800 miles. I have noticed a lot of noise coming from the battery compartment--clicks and such. Does the battery need a heater in the 40 degree range? Other than plugging in the block heater and getting him a blanket and some hot cooca, I don't really know how to keep him warm.

 

We have a 10% ethanol mandate year-round, so it's not that. The refineries usually don't start producing winter blend till October (I have a friend who works at one).

 

20% loss of mileage, sounds like you may have gotten some oxygenated fuel or low BTU fuel. A 25 mile trip the warm up period should not be a major factor. When I had about 4000 miles I started to get complacent, not attentive to techneque, experimented with some techniques that didnt work and had some low averages. Just food for thought.

 

assuming Ford makes use of the US patent granted them a few years ago the level of regenerative braking used in the FEH/MMH is lowered substantially with the onset of cold weather.

ANY non-ABS controlled braking of the front wheels, real (engine compression) or regenerative, can too easily result in loss of directional control should the roadbed be slippery. Even in normal times, warm climate, the patent calls for disabling of the regenerative braking anytine the ABS activates.