First tank MPG figured on paper 21MPG, second 19MPG, third tank 17MPG and last tank 14.7 MPG. Same driving route (Hwy/city) and style. Lie O Meter says 19.6 MPG.

Time to see the dealer?

 

Are you driving the same? That's a massive difference. Do you watch the instant meter? It doesn't lie about your instant mileage as it's generating that graph based on fuel and airmass going into the engine... the MPG figure is conflated by inaccuracies of the fuel level sending unit most of the time.

 

Truck is used only to go the 145 miles to our lakeplace and back (we have 3 other vehicles). 100 miles interstate with Lie O meter showing 22.5-24 MPG @ 75 MPH. 45 miles country secondary roads with meter showing 24+MPG @ 60 MPH.

SUM TING WONG!

 

When did you get the vehicle? Could it be that winter blend gas is hitting your area? I have about 4700 miles on my truck and the MPG seems to be pretty consistent... between 18-19 MPG on paper.

 

It's 6 weeks old. I've babied the hell out of it for a easy break in period too.

 

I'm going to go with that you're getting winter blend gasoline... Hence, worst gas mileage.

 

Got the 14.7 MPG tank after I put a cheapo Rugged E series vinyl Tonneau cover over the bed. Do they kill MPG?

 

No if anything it should help....

 

Are you resetting the "Lie-O-Meter" each time when you fill up?

You are not supposed to baby it just as your not supposed to "Drive it like you stole it!" during break in.

My wife has gotten 25.4, 19.8, 19.7, and 21.6 in hers with just 4 fill-ups with the 36 gallon tank.

I was going to ask if you were letting it idle a long time to warm up but seeing you are in Florida that is out of the question.

That is a huge difference and more than my '14 3.7L between best mileage (17.5) and worst (14.0) when towing a small utility trailer.

 

Bought in June - have about 4500 miles. I did measure the first 1000, then did 2500 miles and averaged 17.1. Reset and measured the last 1000 (about two tanks) and am at about 17.3 but concertedly driving very conservatively.