nyxltregcab

In the past 4 weeks or so, the mileage on my 2012 5.0 Lariat 4x4 has dropped about 1.5 mpg. The truck has just over 3000 miles on it. It had averaged about 16.5 and now is barely getting over 15. It feels a bit sluggish too.
I've searched on here to find older threads about this issue, but those are usually a result of over-sized tires, lifts, etc... I am 100% stock. I thought it might be bad fuel, so I re-filled at 1/2 tank, and it made no difference. Then, I let it get down to 50 miles to go and re-filled, and it's still not any better.
I haven't changed where I drive, when I drive, or how I drive at all. Does anybody have any idea what could be going on??

BxrRebel

Temperature change can be impactful.

Silver FX4

I wonder if gas companies are switching to a winter blend gasoline? Mine is down since I'm using the remote start to warm the truck up a bit on these cooler mornings. I can't think of anything else it could be.

Silver FX4

One more thought...could the cooler temps be effecting the tire pressure?

iphanatik

Its getting down to mid 30's where i live, winter gas would be my guess.

nyxltregcab

You guys could very well be right. It is getting down into the 30's at night here, too. I'm just a little suprised they would switch to the winter blend in the middle of September. Maybe that's normal?? I never noticed this big of a difference when I had the 2010 4.6 3v XLT 4x4. Maybe the 5.0 is a little more sensitive to temps. and blends. I checked the tires and they are at 32 psi all the way around, so they probably aren't the problem. I might try a different gas station next time.

iphanatik

I always plan on my fuel bill being higher sep-march. lol

gwpfan

By any chance have you checked your plug gap yet? Not saying that's the issue but mine just started doing some weird stuff, running rougher than normal and mileage dropped. Guys have reported things running smoother *and mileage increases. Thought it may have been one of the fill ups but on the second fill up, ran it less than 3 gal. left on last fill up it ran a bit better but still not quite right. Took it in and no errors found and they said everything checked out. I plan on checking the plugs some time this week/early next.

https://www.f150forum.com/f70/eco-sp...169457/index7/

MRigs81

I feel like it is the cooler temps as well and maybe a different gas blend. My 2011 Ecoboost is down about 2.5mpg. I read once before that cooler temps can effect fuel milage.

MPETE

iTrader: (1)

cooler inlet air temps will make for a richer fuel mixture, aka slightly less fuel economy. add in the possibility as mentioned for winter blend gas already making its way into the tanks and you have a very good recipe for lower fuel mileage numbers.