Accuracy of MPG display in Dash

[Riccochet]

When towing my travel trailer, MPG can be critical bu in an indirect way. What I really care about is range and how far I can go on a tank or how far I can go on the gallons remaining in the tank.
This is really important when heading west and not traveling on the interstate. For example in nowhere KS when I got to my planned stop and found the small town gas station closed. I needed to be able to know what my range remaining was in order to decide if I would carry on to the next town or turn back to a place I passed earlier that I saw was open.

I don't really believe "hand calculated is any more accurate due to too many variables. But since it usually comes in lower, it's a more conservative estimate on how far I can go.

YMMV, but my 6.4 2500 while towing my 31' travel trailer can roughly go 200 miles before needing fuel. That usually leaves me with roughly 4-5 gallons left in the tank. Just did a trip to Myrtle that is 160 miles from my house, had about 1/4 tank left (according to the fuel guage) when I got to the campground.

My truck when on "E" and reading 0 miles DTE still has 4-5 gallons in the tank as I can only put in 27-28 gallons.

 

[Ratman6161]

YMMV, but my 6.4 2500 while towing my 31' travel trailer can roughly go 200 miles before needing fuel. That usually leaves me with roughly 4-5 gallons left in the tank. Just did a trip to Myrtle that is 160 miles from my house, had about 1/4 tank left (according to the fuel guage) when I got to the campground.

My truck when on "E" and reading 0 miles DTE still has 4-5 gallons in the tank as I can only put in 27-28 gallons.

I usually only go 150ish miles and usually have 10ish gallons left. If I ran it down to only 5 gallons while towing my trailer that would be only around 40 miles range or as low as 3o if it's windy and i ran it down to 4 gal. In my Nowhere Kansas example, that would have resulted in me being out of gas on the side of the road. Keeping a 10 gal reserve gave me 75 to 80 miles to empty which was enough of a difference to get me to the next town. All depends on your comfort level and where you are. I would have extreme anxiety if I ran it as low as you do.

 

[Riccochet]

I usually only go 150ish miles and usually have 10ish gallons left. If I ran it down to only 5 gallons while towing my trailer that would be only around 40 miles range or as low as 3o if it's windy and i ran it down to 4 gal. In my Nowhere Kansas example, that would have resulted in me being out of gas on the side of the road. Keeping a 10 gal reserve gave me 75 to 80 miles to empty which was enough of a difference to get me to the next town. All depends on your comfort level and where you are. I would have extreme anxiety if I ran it as low as you do.

I'll only run it that low if I know I won't be screwed. Weather and driving conditions permitting. I'm pretty good at planning my driving to include truck stops or gas stations that I know will be open at roughly the 150-175 mile mark.

 

[Tulecreeper]

It seems to me pretty accurate. I use an App called Fuelio. I enter information there each time I fill up and it tells me my average MPG.

I have an app called Calculator that does the same thing.

 

[Stan Wetmore]

I have a 2022 1500 Big Horn and it seems good at times and other times off. I imagine it depends on what length of distance it averages out the milage. I fill the tank until it shuts off ever time. I then do a calc for the distance since last fill up and this one. This way it averages the fuel milage over the whole tank. I don't know how the EVIC does its average. I also use a spreadsheet I do like the "Distance Left in the tank" display though. But don't trust it entirely.

 

[WY-Dave]

With the hand calc, the amount of fuel to get "Full" is to variable. as soon as it clicks off, 1 click 2 click etc. And how different pumps click off. On the exact local same pump after the initial shut off I have put in anywhere from 2 to 5 gals until it shut off the second time. Lets say 300/19gals=15.8mpg (3 gals dif) 300/22=13.6 in theory that's 66miles of range on a 32 gal tank.

I just realized that in torque app, there is a digital fuel level and it responds almost instantly. So going to fill to 90%, zero everything out, and the next fill to 90%. To me, the main issue in the hand calc is that the end point (full) is not measured in accuracy and this should minimize this

 

[Tulecreeper]

I have a 2022 1500 Big Horn and it seems good at times and other times off. I imagine it depends on what length of distance it averages out the milage. I fill the tank until it shuts off ever time. I then do a calc for the distance since last fill up and this one. This way it averages the fuel milage over the whole tank. I don't know how the EVIC does its average. I also use a spreadsheet I do like the "Distance Left in the tank" display though. But don't trust it entirely.

I do the same thing. If you watch the EVIC, you will see the constant/continuous change in MPG from one second to the next. If I'm on cruise control and climbing a hill, it will read ~12 MPG, then as soon as I crest the hill and start down it will sometimes climb to 99 MPG for a few seconds before dropping back to 24 MPG. I don't trust it so I just do my own at each fill up. Takes a couple seconds. Just pull out my calculator while the tank is filling and punch in the mileage on my trip-o-meter, and when the pump cuts off divide that by the number of gallons. I never top off so it's always going to be within a cup of gas from fill-up to fill-up.

 

[Tulecreeper]

With the hand calc, the amount of fuel to get "Full" is to variable. as soon as it clicks off, 1 click 2 click etc. And how different pumps click off. On the exact local same pump after the initial shut off I have put in anywhere from 2 to 5 gals until it shut off the second time. Lets say 300/19gals=15.8mpg (3 gals dif) 300/22=13.6 in theory that's 66miles of range on a 32 gal tank.

I just realized that in torque app, there is a digital fuel level and it responds almost instantly. So going to fill to 90%, zero everything out, and the next fill to 90%. To me, the main issue in the hand calc is that the end point (full) is not measured in accuracy and this should minimize this

I can't remember ever "topping off". I let it run until the pump cuts off and I assume the tank is full. I have never filled up, then got back in my vehicle to find that the gas gauge doesn't read hard over on full.

 

[GTyankee]

All of this does not matter even a little bit, when that gas station out in the boondocks, the one that you stop at every year, just before you head out where few travelers have gone before.

When that gas station is boarded up, turn around, cause you may not make it to your camp

 

[JF19Longhorn]

Mine is off about 0.75-1 mpg, and almost always optimistic. It's been correct or pessimistic maybe a dozen times in the 55k miles I've owned it.

 

[jejb]

I hand calculate every tank. The closest mine comes is about .5mpg optimistic, when towing my bass boat. It's about 1mpg optimistic when hauling my bigger trailer. It is as much as 2mpg off when doing an unloaded long distance interstate cruise.

 

[sam darakjy]

When towing my travel trailer, MPG can be critical bu in an indirect way. What I really care about is range and how far I can go on a tank or how far I can go on the gallons remaining in the tank.
This is really important when heading west and not traveling on the interstate. For example in nowhere KS when I got to my planned stop and found the small town gas station closed. I needed to be able to know what my range remaining was in order to decide if I would carry on to the next town or turn back to a place I passed earlier that I saw was open.

I don't really believe "hand calculated is any more accurate due to too many variables. But since it usually comes in lower, it's a more conservative estimate on how far I can go.

Well I surely wouldn't be looking at either if I'm letting my gas go that low.

 

[bmyfe]

Well, I'm gonna chime in here boys. I have a 2023 and opted for the 6.4 after doing a bunch of research online, youtube, fuelly etc. I have 3k miles and the mpg is no where near what the onliners say. I pulled a 7k trailer this weekend and got 6.7 mpg combined and I wasn't hammering it all. I really wish I would've bought the diesel. I'm kinda pissed.

 

[06 Dodge]

Well, I'm gonna chime in here boys. I have a 2023 and opted for the 6.4 after doing a bunch of research online, youtube, fuelly etc. I have 3k miles and the mpg is no where near what the onliners say. I pulled a 7k trailer this weekend and got 6.7 mpg combined and I wasn't hammering it all. I really wish I would've bought the diesel. I'm kinda pissed.

Sorry you had to learn the hard way, all of the problems people have posted all over the internet about the newer Hemi is why when it came time to replace my old 06 CTD I bought a 2022 2500 with a CTD...

 

[yrraljguthrie]

"Gas could go up to $10 a gallon and it wouldn't change my driving habits one bit."

So those of us who think differently from you should never buy a truck?

 

[dhay13]

Well, I'm gonna chime in here boys. I have a 2023 and opted for the 6.4 after doing a bunch of research online, youtube, fuelly etc. I have 3k miles and the mpg is no where near what the onliners say. I pulled a 7k trailer this weekend and got 6.7 mpg combined and I wasn't hammering it all. I really wish I would've bought the diesel. I'm kinda pissed.

Sounds low. Should be a little better. Maybe after a few thousand miles. Son towed his 8100lb TT almost 10,000 miles with his 2018 6.4 4.10's and averaged about 8.5 hand calculated. Still not great but better than you got. He towed the same TT with his 2021 2500 Cummins and got 12 MPG

 

[Tulecreeper]

"Gas could go up to $10 a gallon and it wouldn't change my driving habits one bit."

So those of us who think differently from you should never buy a truck?

No, but don't buy a truck then gripe about the mileage.