I have a 2016 F150 SCREW with the 2.7 EB. I have had it for 6 months and averaged 21-22 mpg for the first 5 months. Average gas mileage has fallen 3 mpg according to vehicle computer since weather turned cold. This includes driving on dry roads. Is this common for mileage to fall this much in cold weather?

 

I don't know if it's true where you live, but here in New England there is a change in the gas formulation in the winter that results in poorer mpg.

 

Winter gas blend here in Oregon now. I generally lose 10% which a small amount of that may be attributed to warming the truck up when its very cold.

 

Every vehicle I've had in recent memory drops a few MPGs in the winter.

 

Definitely not an EcoBoost thing, it affects all vehicles. Everyone likes to blame winter blend gas, but I think the majority of the blame goes to wind resistance and longer time spent warming up. My truck almost never idles, and my fuel economy is substantially higher at 30° than it is at 0°, all within the same tank of fuel.

I track each tank, and the trend line for fuel economy has steadily gone down for each as the weather got colder. That includes a 3.7L Ford Transit van, and a Kia Optima sedan.

 

I have a buddy with an '86 F150 300 six with a 1bbl carb and an OD manual tranny. We've tuned that thing to the hilt and he's getting right at 20 MPG with his daily driving. He's tracked every drop of fuel that goes into it for the last 4 years, and you can easily see where the MPG goes south each year. It seems to occur with a tank of gas each year and stay down until the spring.

He doesn't idle it to warm it up, and for the most part takes the same route to/from work 5 days a week. The truck rarely goes on weekend trips, and it's one big trip each year is to my house for the Okie GTG. He describes his driving as like a grandpa with an eggshell between his foot and the throttle.

Given the above his MPG is pretty consistent - until it changes. And it looks like there are at least two factors to the change - gas formulation and temp. The most significant change seems to come suddenly, and must be due to gas. But, it continues to go south for a bit each year after the gas change, which seems to be associated with temp.

 

Having used a Scanguage since it first was released on several vehicles, I noticed that the amount of time taken for engine warmup has a big impact on fuel mileage. The quicker the warm up, the better the fuel mileage for that segment of the commute.

This F150 warms up very fast. I've observed Temps as high as 210 degrees before the grill shutters open up and the temp drops to 198 degrees.

I don't know why the intake air temperature is 15 to 20 degrees hotter than the outside ambient temperature. Maybe it's the location of the sensor, or ford intention to help with emissions by raising the intake air temp. Maybe someone else can shed some light on this mystery.

 

I'd agree with that, Neal. Warmup time varies hugely depending on what the engine is doing, though.

Today it took six minutes for my temp gauge to indicate full operating temperature; the last three minutes of which were spent at 70 MPH. One particularly cold morning I had to idle to clear the windshield, and after 13 minutes the gauge had barely moved, and I had consumed nearly a half-gallon in the process just sitting there idling. I much prefer to drive away immediately, but sometimes need the defroster to do so safely.

 

If it's idling in gear, it might speed up some more?

 

I'm thinking maybe not a huge difference in engine warm up, but maybe it would help to warm up the tranny.

The gallons per hour jumps up to 5.7 from 4.4 when in drive and the defrost on. And I saw the transmission temp stablize at 172 during idle, but quickly increase to 185 in just a minute of idle in drive.

I think the grill shutters go along way toward decreasing the warm up time for these trucks.

 

I always used to think so until a couple of years ago. On my '97 4.6L Lincoln, fuel consumption was higher idling in neutral than it was in drive. I always assumed that the added engine load would mean the opposite, but the ~200 RPMs higher it would idle in neutral burned more fuel, thus created more heat. Haven't checked fuel flow rates for either of my newer trucks, so I couldn't say with an EcoBoost. I would assume the principle would be the same though.

 

Here's something you can try that might surprise you. You'll need two 8 ounce disposable plastic cups and a small plastic funnel (one with about a 3/8" hole in the neck) and a watch with a second hand. Put 6 ounces of your favorite 5W-30 motor oil in each cup. Put one in your refrigerator's freezer and leave the other on your kitchen table for about an hour. Put the funnel in the top of the oil bottle, and pour the room temperature oil thru it and time from the beginning of the pour till the funnel neck is clear again. Now do the same with the oil from your freezer.


What you'll discover is that the idea that 5W-30 oil is 5 weight when cold and 30 weight when hot is a popular misconception. There is sooo much more to multi viscosity motor oil than that, and if you're really interested in the details, Google is your friend.


This can have a measurable effect on fuel mileage in the cold weather along with all the other issues others have mentioned. That's why you'll usually find a statement in most owner's manuals about not needing to warm up a modern engine in cold weather. Just start and go but keep the speed down for a couple of miles just to minimize pumping losses.

 

IMHO...falling 3 mpg is not that bad. What octane are you running? Do you fuel with winter blend now in the winter where you live?


biz

 

I'm inclined to go with the effects of the cold weather and warmup. Living in a mild-climate California, which has had winter-blend fuel for some time, I don't see this kind of drop in fuel economy.

I think I do see "maybe" 1 MPG difference due to the change in the fuel. Sure it gets "colder" around here in winter time, but we rarely see freezing temperatures. People start jumping around and loudly proclaiming "Brrrrrr..." at around 40 degrees F.

So I would say a small amount of the MPG difference is due to the fuel change, and the rest is just the side effects of cold oil, warm up, etc.

 

If it makes you feel any better, my 2015 Sierra dropped to 9.8 mpg this winter, with city driving only. Pretty disappointing for a truck that claims 16 mpg city.

However, like everyone is saying, winter has quite an impact on fuel economy.

For me it's:

1) Remote start every morning, leave truck running when dropping off kids
2) Colder temps drops tire pressure
3) 0-30-0 mph driving only
4) Winter fuel

There is likely something else going on with mine though.. I've had numerous issues with this truck and can't wait to trade it in for an F-150.