Jaker999

I've noticed on my 2012 FX4 screw Ecoboost with 3.73 gearing that my gas mileage has been worse with the lower temperatures (0-25 degrees Fahrenheit out). My mileage on the truck is 6000 miles so it is still probably being broken in. I fill up at the same gas stations on each end of my 280 mile trip. Maybe a winter blend of fuel is worse for mileage?

Just wondering if anyone else has noticed a similar situation. I usually get 22-25 mpg at 60mph now I was getting 18-21mpg on my last trip. I'm not complaining by any means! I'm just curious.

HCFX2013

Gotta be the winter blend. The Ecoboost LOVES the cold weather. I find mine has serious ***** and is very efficient when it's cold. When it's cold here, it's snowy and when it's snowy I'm always in 4WD, which will kill your mileage anyway. I'd just write off winter for mileage period.

Coaster60

Yep, your right about winter blend fuel being worse for mileage. Basically the fuel is oxygenated taking up space and reducing power output of the fuel. I've always wondered if winter blend actually meets the octane levels posted.... Anyway, you'll see a MPG decrease which is another reason to look forward to the spring and summer months.

2010stx4by4

Also take into account the viscosity of the oils in the various parts of the truck taking longer to warm up and putting more strain on the vehicle.

iphanatik

I usually get 2mpg avg less in the winter. Winter gas, more idle time, pulling stuck friends out of the ditch, ect.

Ssls6

It's the gas. 25 years ago this was not true. Almost the opposite where in the summer most cars would ping a bit in partial throttle load.

dave91gt

I lost a good 2mpg with my 5.0 as soon as the winter blend hit the tank. I'm with the guy that said winter is a time to ignore fuel mileage.

jonbar87

It's not just the gas. Cold air is denser than hot air, so essentially the engine intakes more air when it's colder out. Why do you think cars make more HP in cold weather vs when it's hot? (dyno proven) It's because the AFR's must remain constant, and therefore more air will always = more gas. That's the main reason why your mpg's have dropped. The winter blend has little if nothing to do with it.

2010stx4by4 was also correct with his response.

truckerdude

my short city drives 1-5 miles, mpg in the winter drops by 2mpg. Has nothing to do with winter blend fuel. The engine is colder so it takes longer to get up to operating temperature. Heck in the summer it takes about 10 miles of driving to get the tranny up to operating temp, in winter of course it's worse. On longer trips during the winter I see none or very little difference. If winter blends have an effect its not much, oh I live down south not yankee land so our fuels may be different

Coaster60

Google the difference between Winter and Summer Fuel Blends.

"Well, basically, winter blend gasoline has a larger percentage of butane in it. And since butane is cheaper and has less energy, winter blend thus costs less and gives us a lower MPG when we burn it. So it’s a wash, right? Eh, maybe. Your vehicle miles per gallon typically will drop 2-8% when you start filling up with winter blend. Unfortunately, evidence suggests that the common price decline is 2-4%."