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??