GEN 1 Lower than normal MPG?

[marcm]

So I'm a long time reader 1st time post. The issue I am having is for the entire life of this truck I have consistently maintained between 14.7-15.2MPG (city/highway). I recently took my truck in for its 100,000 tune up with the only dealer that has ever worked on this truck. After the tune up while I did notice a little better throttle response I also noticed my fuel economy went down? It started at 10.9MPG & now after 7,000 miles it has only creeped up & settled into 11.7MPG? I voiced this issue with the dealer at my last oil change & he said he would have his tech look into but nothing was found? Does anyone have have ideas what may have changed? I had hoped after the tune up the MPG going up slightly or at a minimum staying the same. Attached are photos (to prove it hapened) FYI if anyone is looking for a great truck I will be posting this for sale shortly (I have a 2019 on order).

 

[Deleted member 12951]

That thing is hideous, damn [emoji23] . When did you put that heavy ass bumper on, before or after the tune-up? Maybe part of the issue.

Did you ever confirm your MPG instead of relying on the computer by actually measuring the gas to how many miles manually?

Also, what exactly did the dealership do for the so-called tune-up? I’ve seem that term used loosely and means different things done to different folks.

 

[marcm]

Yes, I "made it my own" & the bumpers have always been on (I prefer a bumper with some protection in the event I ever need them). Good idea I will confirm based on actual mileage on my next fill up. I am waiting on a copy of my maintenance records to see exactly what was performed?

 

[B E N]

Check the plug wires, make sure none of them are loose, check the plugs and make sure they are tight.

 

[marcm]

I was thinking plugs/wires as well. It's that something that should've been replaced at 100,000 miles with the tuneup ?

 

[Andrew72]

Uh, I wish I could say I consistently get 15 mpg. 10-11 sounds pretty normal

 

[Denyen]

Just got back from a road trip in my 2018 screw. Went 590 miles on one tank, 20.1 mpg. Mostly highways mountain driving and 65 mph. Also in normal mode. I know sport mode drvies my mpg down a little.

Maybe the tuneup changed the tune a little.

 

[Canuck714]

I think the before tune up mileage was wrong. Very few 6.2 Raptors do better than 12-13mpg average.

 

[Sozzy12]

Bad gas?

 

[prowakeskater]

Jesus Christ that thing is ugly. put the stock Gille and oem style HIDs in.