Recently picked up my 2025 Rebel and the mileage is showing about 15 MPG.

[fiestorm59]

What is going on? Watched videos of trucks with this engine and they were registering 23 MPG HWY. My truck has the 33 gallon tank and it was registering 40 miles to empty and when I filled it up it only took 27 gallons. Seems that the software must be an issue.

 

[OutLaw15K]

Unlikely it's a software issue. It's possible you may have an electrical or mechanical issue.

 

[Gren71]

if its brand new it still needs to break in, and the miles until empty needs more data to build an accurate picture of how far you have until you dead in the water. That combined with winter blend gas will add up to lower than expected mpg easily. With my 23 Bighorn it took a couple thousand miles before the mpg leveled out and the distance until empty was accurate. My distance to empty also tanks after every time I tow my camper and it takes a tank or two to get back to normal. Also remember MPG is VERY user dependent...I do a LOT of highway driving and use my cruise control set to 65mph nearly all the time during my 40mile drive in to work, and same on my way home. With highway tires and no significant suspension mods I get 20-21, which is about right for my truck. If i mix in nearly any stop and go travel it drops some. I was over mpg conscious with my gladiator and it sort of became an obsession. With this ram I started down that road and thankfully was able to stop while I was ahead. I pulled the mpg reading off the cluster and left the miles until empty. Now I just drive and it is what it is...which is a freeing state of mind when it comes to MPG and a Hemi. Though I DO know I will likely end up doing the 33gallong tank mod at some point...having the baby tank it gets annoying filling up every week and only having about a 200 mile range while towing.

As far as the tank not filling all the way. I have the 23 gallon tank and it never fills all the way to 23 when I fill up. I chalk this up to me never running the truck until its sputtering and truly empty. most tanks still have a little fuel in them, a gallon or so, even when they read empty on the cluster. Not saying theres a problem, but I am saying there probably isnt any problem. If your really concerned you could run a little experiment of sorts. Fill up EVERY TIME its at exactly half and record the volume of fuel you put in. If its within a gallon or two every time then im sure its normal. Or you could measure the volume filled at what ever quarter of a tank your on. Each quarter is 8 gallons for you, assuming 1 galling is left in after its "empty. So if you fill up while its at 3/4 tank...it SHOULD get 7 or 8 gallons of fuel in at a time. Mind you im not an engineer and god knows there is probably some super fancy extra reserve or hold out tank or some such that I have no idea exists and it leads to the basic numbers being skewed.

 

[SD Rebel]

Rebels get bad gas mileage, it's the nature of trim.

Stellantis EPA mpg rating is blanket stated across all trim lines, the higher mpg you have seen documented was probably from street tired 1500s, Rebels with their 33" ATs will never match.

Unless you hypermile, you won't come close to the window sticker rating.

I can get close to my window sticker 15-17 mpg in my Rebel if I drive very slow, very light with the application of the throttle, essentially willing to anger Grandma's in Prius's driving behind me, but if I drive normal I'm probably in the 11-13 mpg range.

 

[DEG]

Everything in your post seems perfectly normal. Stop overthinking and just drive.

 

[3phonesrob]

What is going on? Watched videos of trucks with this engine and they were registering 23 MPG HWY. My truck has the 33 gallon tank and it was registering 40 miles to empty and when I filled it up it only took 27 gallons. Seems that the software must be an issue.

When I left the dealership with my truck it had a full tank and showed 200 miles of range (also with a 33 gallon tank), and the low fuel light came on at 1/4th of a tank left on the fuel gauge. I filled my tank at about 400 miles driven and it only took 21 gallons to fill, so like others have said it should recalibrate.

 

[TopazM3]

I have a 2012 1500 Hemi, owned since new. It has the 33 gallon tank. In 120,000 miles, I have never once put more than 28.1 gallons in at a fill up. That includes when showing 0 miles remaining. Most fill ups from “empty” are in the 27 gallon range. I find this pretty annoying since it’s as if I really have a 28-9 gallon tank. I tow a lot, so I like as much range as I can get.

 

[redmyst]

I have over 7k miles on my 2025 rebel, same build out, 33 gallon tank.

My experience is:

Not once filling up have I hit 30 gallons on the pump, even when it says I have less than 40 miles till empty.
MPG is never going to get over 15/16 with city/rural driving. I am doing a long trip up to Alabama this week so i will see more highway but I'm betting I don't get the 23 MPG they stated.
I have run several tanks with 87, stays about 14.5 to 15, 89 stays 15 to 15.5, and 93 stays about 16 but more power.

I have a heavy foot but not that heavy.. outside of going off roading, I am never in 4 WD and I usually roll in aero mode on the air suspension.