Woolaroc

Hi All,

For the past couple tanks I've noticed a large drop in fuel economy and not sure what the cause may be. I know winter fuel typically has a small drop, but this is the 3 winter I've had the truck and it hasn't been this significant. Generally in the city I'm getting around 15 MPG and 17MPG on the Highway (in winter). The past two tanks I've gotten around 12 in the City and 15-16 on the Highway.

I have around 38k miles and running the canned SCT 91 Octane tune. I change my oil regularly and have had it in to the dealer for normal check ups. I did get new (larger) tires in September (285/65/R18 on stock rims) and noticed a slight drop with those, but not this bad.

Has anyone else noticed large fuel economy drops, or should I take this into Ford. Not sure what I would tell them besides my fuel economy has started to suck.

2012 F-150 XLT Ecoboost SuperCrew, 3.73.

Tothemax

Tough to say. Could be fuel, conditions, air pressure, 4wd use, etc.

I would check your spark plugs and make sure they are gaped properly. Also make sure they are not cracked and are torqued properly.

How is your air filter? Mas Air flow sensor?

MadocHandyman

Has it been bitter cold during the past two tanks?

SkiSmuggs

Mine drops about 3 mpg every winter. It usually starts showing up once winter really sets in around December. I have found that using Mobil 93 instead of Gulf 87 helps some.

Woolaroc

I didn't think about the spark plugs, I've seen some threads about issues, but haven't read any of them...
Air filter should be fine, I get my oil changed regularly and the air filter is changed at the same time.
MAF should be fine... Usually when there is an issue with that it throws a code, right?


I wouldn't say it's been "bitter cold" during my driving times it's probably averaged around 25*, but the past week it's been in the 50-60's.

Woolaroc

I live and work in Bartlesville, OK... I run Phillips 66 91.

Tothemax

Make sure you torque them correctly. They can crack quite easily.

SkiSmuggs

Also a TopTier gas.

brucesears

Guys from all over have reported worse mpg drops this year, it has to be the gas.

vozaday

^ I agree, this year I am down almost 4 mpg, last year it was 2.