Your ACTUAL gas Mileage with a 5.7 Hemi

turkeybird56 · Sep 26, 2022

njjeff201 said:
My vehicle says around 19 plus. I never checked by actual miles. I'll try and see what happens. Have my tire pressures at max... 55 lbs cold. 2021 Longhorn ECO with 3.92 rear.

Running max pressure, hmmmm, not something I would do unless towing max weight, but that is just my very low humble opinion.

wvfarrier · Sep 26, 2022

I average 17-18 but its mostly city driving

Cash22 · Sep 26, 2022

Taspeace said:
i bought a used 2014 1500 Big Horn with a 5.7 hemi and I use 87 octane gas in it. My dash computer shows the gas mileage as about 10% better than what I calculate when I divide my miles driven by the number of gallons burned. For example, my "Trip A" readout that was reset when I last filled the tank said I had averaged 19.6 MPG. My hand calculation for the same tank of gas showed that I averaged 17.6 MPG. This has been pretty consistent and the truck always reports better mileage than what I'm actually getting - never worse.

How accurate is your mileage calculator?

You should be happy with either mpg. Wish I could get that.

sam darakjy · Sep 26, 2022

How many times does someone have to post about gas mileage with a 6k lb truck with a V8 engine. How can a small change up or down change anything in your financial well being. Common sense would say don't stomp on the gas,drive the speed limit, limit the weight in your truck and be done with it.

Mike Smith · Sep 26, 2022

I get on average 17.8 using 93 octane because of the tune on my engine. Diablo Sport.

SlothRam · Sep 26, 2022

2017 2500, 6 Speed, 3.73 Axle Ratio, 20 inch AT tires, I get 14 MPG on 87, with or without my topper. Mostly driving in town or back roads at 65.

Douglas Walouke · Sep 26, 2022

I have the exact same issue on mileage. I track mileage and service using an app called Fuelly. Consistently about 10% lower than what the car says on the dash.

Douglas Walouke · Sep 26, 2022

I have the exact same issue on mileage. I track mileage and service using an app called Fuelly. Consistently about 10% lower than what the car says on the dash

Jerrybob · Sep 26, 2022

20 to 21 mpg consistenly.....when towing.....16 to 17 consistently. Dash and hand calculation are almost identical......life is good.

El Guapo Phil · Sep 26, 2022

My 2016 Ram Big Horn gets me about 16.5 to 18 mpg depending on the roads I travel. Remember, I am in Belize and the road are not all that great, especially with intermittent highway speed bumps. On the straight away I do get 21 to 23 mpg. I am happy with the mileage and with my purring Ram.

Siff · Sep 26, 2022

Is the question regarding the discrepancy between the truck’s reported MPG and the hand calculated MPG? Or what hand calculated MPG people are getting?

For me, the truck calculated MPG has always been within 5% of hand calculated, but I also kept it stock. Any change made to the truck that the truck isn’t calculating for will throw that number off in either direction.

The most common culprit is non-OEM tires, as even 1/2” larger will cause the MPG numbers to be off quite a bit (and the Speedo and odometer to be off by a much smaller amount).

ffmedicmt · Sep 26, 2022

I have a new 2022 6'4 box Laramie with 3.92. I get 9-10 mpg towing my 26ft 5th wheel. I get 13 MPG towing my 19 ft Aluminum boat. I get 15 MPG not towing if I go over 65mph. Best I have got is 17 MPG staying under 65. I HATE the small tank and wish I had ordered the 33Gal. It pulls everything like a dream and I'm glad I got the 3.92 Just get the 33 Gal!!!

fish220sr · Sep 26, 2022

Have a 21' 1500 Limited with 3.92 rear and Hemi e Torque.Put Nitto Ridge Grapplers 285/65r22 on truck MPG reads 8.6. Ran the truck for a week prior MPG 9.6. Gas mileage was not considered in purchase or in tire choice. 9+ MPG is a bit Brutal. My 22' SPWB Charger gets 11.1 MPG. Had many Tahoes,Suburbans, and Diesel Pickups all 10 MPG or better. Love the Ram with the Hemi and 3.92's. What are you going to do? Worst ever was a 460 ci Ford F-350 10' Dump. 1 MPG.

dmcent63 · Sep 26, 2022

From the time it was new I’ve averaged between 13-15mpg. to inch above 15 meant soft peddle starts and always staying below 55. I struggled with that one. The only time I’ve ever seen 17 was on longer steady speed runs on the interstate. As far as the accuracy of the EVIC, the two or three times I have actually done the math to compare, they were close enough not care.

Mando Mark · Sep 26, 2022

My 2019 RAM 1500 Classic with the 5.7L Hemi (4x4 Quad Cab) actually gets about the same mileage as my 2016 RAM EcoDiesel did - AFTER they (FCA) screwed with the computer for their emissions fiasco on the diesel. (Plus gas is currently well over a buck a gallon cheaper than diesel now.) Anyway, I've taken two long road trips from Michigan (to Georgia and Florida and back, respectively) and averaged 22.5 mpg with the truck. I don't stomp on it when I take off from a stop, and always drive at the posted speed limit.
Pulling my 25', 6000 lb RV it gets less than half of that - 9-10 mpg. And that's usually driving 5 mph under the posted speed limit. So while I've got plenty of power with the RV, I tell people "It'll pass anything except a gas station!"

Dieldrin · Sep 26, 2022

2021 Laramie - 305 55r20 Ridge grapplers the 50lb SL version

14k miles
11.34 MPG average
less than 10% highway driving
10% towing boat or small travel trailer

pjs386 · Sep 26, 2022

You're just about right according to my experience. Long highway trips will show 24-25mpg on the dash but calculate to about 23mpg (I'm not complaining :33:

). Around town with some highway and mostly in town driving, I will show 20-21+ on dash but calculate about 18-19 mpg!

16MaxSteelOutdoorsman · Sep 26, 2022

18 back and forth to work, three stop lights, 14 miles, speed limits 35, 45 and 55. The best I got was 20 mpg to FL and back in hot weather.

jimmyfjk · Sep 27, 2022

well i feel but hurt. i have a 2021 rebel 1500 four door 4 wheel drive and get an average of 11.5mpg. No matter how i drive. That is mixed city/highway. i drove a trip of 300miles and took it easy just to see what i could get. Best was 15.5 hwy. fourwheel drive hurts it and so does all the accessories with the weight it adds. I have the air suspension system that adds weight also.

MikoS · Sep 27, 2022

Taspeace said:
i bought a used 2014 1500 Big Horn with a 5.7 hemi and I use 87 octane gas in it. My dash computer shows the gas mileage as about 10% better than what I calculate when I divide my miles driven by the number of gallons burned. For example, my "Trip A" readout that was reset when I last filled the tank said I had averaged 19.6 MPG. My hand calculation for the same tank of gas showed that I averaged 17.6 MPG. This has been pretty consistent and the truck always reports better mileage than what I'm actually getting - never worse.

How accurate is your mileage calculator?

It can be to do with the tire size that is saved in your system. If your tires are not standard then it will be wrong.
If you have AlfaOBD or access to someone who has, it is really simple to edit the tire size. You can even pick the tire make and spec eg. Goodyear Wrangler HP P265/70R17 or whatever tires you have. (not that the computer needs any more than the diameter of course... yet it can be done) This would correct your speedo as well as the MPG shown on the panel. My truck came with different tires to what the computer was figuring on, so my shown MPG actually showed worse after resetting it...

but at least it is spot on accurate now. With AlfaOBD you can also just enter the circumference if that is easier for you.

Your ACTUAL gas Mileage with a 5.7 Hemi

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