Hi all.I know that winter gas is less efficient.I know that the gas meter lies (but its realvant: if 3MPG off, it is always 3 MPG off)So, my question is:Can anyone think of a reason that my 2014 Dodge Ram 2500 6.4L with 103,000kms on it, would start getting worse and worse gas mileage?When first owning the truck, on average I was around 18L/100KM.Gradually, I am getting around 24L/100KM.(or around 10MPG) and I am not towing anything. I do know that I have reduced my highway travel a bit, but is anyone else seriously getting this type of result?I am getting around 500km for 100L of fuel.My dealership has been zero help!

500 km per 100L is 12 mpg, which is exactly what Fuelly says is average for your truck. Kind of sucks but that's what I'd expect out of a big gasser not doing a bunch of unloaded highway miles.

The sad thing about computerized vehicles the computer can make adjustments to keep the vehicle seemingly running correctly. Fuel mileage is a way to track problems that you cant feel in performance but doesn't tell you the problem.

I would replace the air filter, plugs/top shelf plug wires) and run some quality gas treatment through it. Buy gas from a quality name (Chevron, Sinclair) and see if you find some improvement.

So you've gone from 13ish mpg to 12ish mpg. Change the readout on the dash to oil pressure or tire pressure or something other than fuel mileage. That usually helps with the gauge watching.

Gas milage on Ram 2014 RAM 2500 6.4L | Good Sam Community

dodge_guy
Explorer II
Feb 24, 2019
eHoefler wrote:
You should be on your 3rd set of spark plugs, they have a 30,000 mile (18,600kms) interval.

6.4 goes 100k on plugs.
Grit_dog
Navigator
Feb 23, 2019
samhain7 wrote:
Grit dog wrote:
So you've gone from 13ish mpg to 12ish mpg. Change the readout on the dash to oil pressure or tire pressure or something other than fuel mileage. That usually helps with the gauge watching.

I realize it says 24 when it should say 25 (sometimes 26)
That may not seem like a lot to you but with gas prices where I live that is a sudden $8 or more in fuel costs per 100km.
Not sure turning off the display is the best advice.

That was tongue in cheek, but being winter can have a bit to doo with it.
You could be having a slight issue like mentioned above, but at that low of miles and that new, it's unlikely. Check that the engine is getting up to full temp and not unnecessarily running rich. Assuming all other basic maint is up to par.
ib516
Explorer II
Feb 23, 2019
eHoefler wrote:
You should be on your 3rd set of spark plugs, they have a 30,000 mile (18,600kms) interval.

30,000 miles is about 50,000 Km.

Spark plug change interval is 100,000 miles or 160,000 Km for the 6.4L Hemi in the 2500/3500 Rams according to the manual.
MountainAirMan
Explorer
Feb 23, 2019
Has your tire inflation been checked during this period? Any chance you may have some brake pads dragging due to caliper pistons sticking or brake hose internal collapse?
eHoefler
Explorer II
Feb 23, 2019
You should be on your 3rd set of spark plugs, they have a 30,000 mile (18,600kms) interval.
mtofell1
Explorer
Feb 23, 2019
Winter fuel and stop/go driving absolutely kill the MPGs on these trucks. I do a mix of driving and often only see 11ish this time of year. I do a few auto-starts when it's cold too which, of course, kills it further (but at least I'm warm :)) - same truck, 2014 6.4 Hemi 4X4.
camp-n-family
Explorer
Feb 23, 2019
Winter fuel and longer idle/ warm up times.
ib516
Explorer II
Feb 23, 2019
Do you have one of the cr@ppy reusable air filters in it like a K&N?
samhain7
Explorer
Feb 23, 2019
Grit dog wrote:
So you've gone from 13ish mpg to 12ish mpg. Change the readout on the dash to oil pressure or tire pressure or something other than fuel mileage. That usually helps with the gauge watching.

I realize it says 24 when it should say 25 (sometimes 26)
That may not seem like a lot to you but with gas prices where I live that is a sudden $8 or more in fuel costs per 100km.
Not sure turning off the display is the best advice.
Krusty
Nomad II
Feb 22, 2019
Thermostat starting to stick open a bit. Oxygen sensor(s) getting worn. Lots of things can contribute to fuel consumption.