2021 RAM 1500 Limited is Getting 8.5 MPG, Easy Driving, No Aftermarket Upgrades or Mods

[mikesamson]

I'm excited to be part of the RAM community! I recently purchased a 2021 RAM 1500 Limited with 53K miles, and I’m absolutely loving the truck. Upgrading from a JKU, the difference in drive quality is night and day.

That said, I do have one concern regarding fuel economy. I fully understand that I bought a 5.7 HEMI with eTorque—it's a large, heavy, and not-so-aerodynamic truck that naturally consumes a lot of fuel. I’m not expecting the factory-rated 17 MPG city / 23 MPG highway, but my actual results seem unusually low.

According to the truck’s Avg MPG screen, I’m only getting about 8.2 MPG. To verify, I manually calculated after today’s fill-up and got 8.5 MPG.

Here are some details about my conditions that may help diagnose the issue:

• I did reset the trip computer after the dealership, knowing that test drives can produce low MPG.
• Outdoor temperature range over that past week has been between 0° - 12 ° in my area.
• I filled up with mid-grade 91 based on factory recommendations.
• I have eTorque start/stop activated.
• My ride height is at an efficient "Aero" setting according to the system.
• I'm driving in 2wd.
• This has been all local driving, I have yet to take it on the highway.
• I'm driving extra easy, just hoping to bump the MPG to prove myself wrong.
• I have been remote starting it in the mornings for about 10 minutes.
• 22" rims with standard all-season tires.
• No aftermarket engine upgrades or lifts.

I feel like the MPG is very low, and was expecting somewhere around 14 MPG city from this truck. Before posting this, I searched multiple threads for potential causes and solutions, but the answers range widely—from something could be wrong to just suck it up, it’s a pickup. As a first-time truck owner, I’d really appreciate any insights or advice on whether this is normal or if there’s something I should check. Any guidance would be greatly appreciated!

 

[PurpleRT]

A few things going against it the cold season, you’ll be on winter blend gas, the avg mpg will average out as you go about doing your everyday driving.. idling, short test drives while on the lot could be the reason, it might take some time for it to go back up and always hand calculate.

What gearing also 3.21 or 3.92.. the tradeoff with 3.92 gearing will take some mpg away from you.

 

[jkm312]

I would hand calculate the next tank's mileage and see what you get. It will get you out of the trucks history of mileage.

 

[mikesamson]

I would hand calculate the next tank's mileage and see what you get. It will get you out of the trucks history of mileage.

I hand calculated it today and it came out to be 8.5 mpg, slightly better than the computer's 8.2 mpg, but still surprisingly low.

 

[jkm312]

I hand calculated it today and it came out to be 8.5 mpg, slightly better than the computer's 8.2 mpg, but still surprisingly low.

Ive got the same temps as you, unfortunately. Mine is garaged. My practice is to start it, let the RPM's drop to 800 and go. Heated seat and steering wheel keeps me happy enough until it warms up. I just drive it easy until it does warm up. I'll average 12.5 to 14 mpg this time of year. I would check your air cleaner, tire psi then check to make sure the throat plate is clean and opening like it should. Might be time for a tune up if this simple stuff doesn't work.

 

[kapinallinen2]

I have been remote starting it in the mornings for about 10 minutes.

That plus short local trips could do it.

 

[mikesamson]

A few things going against it the cold season, you’ll be on winter blend gas, the avg mpg will average out as you go about doing your everyday driving.. idling, short test drives while on the lot could be the reason, it might take some time for it to go back up and always hand calculate.

What gearing also 3.21 or 3.92.. the tradeoff with 3.92 gearing will take some mpg away from you.

I'll be monitoring it, thank you. As far as the gear ratio, I'm actually not sure. The window sticker lists it as "8-Speed Automatic 8HP75 Transmission".

 

[mikesamson]

Ive got the same temps as you, unfortunately. Mine is garaged. My practice is to start it, let the RPM's drop to 800 and go. Heated seat and steering wheel keeps me happy enough until it warms up. I just drive it easy until it does warm up. I'll average 12.5 to 14 mpg this time of year. I would check your air cleaner, tire psi then check to make sure the throat plate is clean and opening like it should. Might be time for a tune up if this simple stuff doesn't work.

Thank you, I'll keep all that in mind. This thing isn't fitting in my garage at the moment, I have to do some spring-cleaning for a second vehicle. But I'm sure running it in the mornings doesn't help.

 

[Rock Crawler]

Geez, that’s bad. My 2005 4.0L LJR with a 3/2 lift on 35’s averages 9-10 mpg. And that thing is like driving a cinder block into a 50 mph headwind. I had a 2020 Ram 1500 with the 5.7 Hemi and eTorque and it averaged 13.8. And I’m not light on the throttle. Something doesn’t add up.

 

[law]

averaging 11.8 mpg with -30 degree celsius weather the past 2 weeks. I have it in 4auto and also enjoy pressing the skinny pedal fairly often. I have been doing primarily city driving
mine is a longhorn that has the same 22" wheels that yours will have, but i specifically opted to not get the etorque and air suspension. from what i recall, air suspension and etorque should both improve mpgs by a marginal amount.
the only thing i'm not doing is idling it for a long time in the morning (garage).

 

[dajogejr]

You can find your rear end gear ratio on that same sticker, it’ll say 3:21 or 3:92
Running it in the mornings doesn’t help…but I do the same.. I don’t blame you.
As you have time, fill up, hit the freeway for a nice drive, set the cruise at 70 for a stretch, return, fill up, see where you’re at.
Between local short trips, prior history, and remote start…

With 3:21, lot of remote start action (single digit/teen morning temps up here) and about a 5 mile city drive to the office, I’m still in the 14 range, and I’m not easy on the fun pedal.
I’m not sure how you’re in aero mode at 0MPH.
If I recall, and based on my 15 and 23 limited trucks, aero is once you hit something over 60MPH to get there (I think its like 62MPH without looking it up) and you have to maintain at least 55MPH (again, not sure, not looking it up) to keep it in aero.
It should be speed activated. And frankly, it’s half an inch lower than standard.

8MPG is old V10 mileage days…lol.

 

[mikesamson]

You can find your rear end gear ratio on that same sticker, it’ll say 3:21 or 3:92
Running it in the mornings doesn’t help…but I do the same.. I don’t blame you.
As you have time, fill up, hit the freeway for a nice drive, set the cruise at 70 for a stretch, return, fill up, see where you’re at.
Between local short trips, prior history, and remote start…

With 3:21, lot of remote start action (single digit/teen morning temps up here) and about a 5 mile city drive to the office, I’m still in the 14 range, and I’m not easy on the fun pedal.
I’m not sure how you’re in aero mode at 0MPH.
If I recall, and based on my 15 and 23 limited trucks, aero is once you hit something over 60MPH to get there (I think its like 62MPH without looking it up) and you have to maintain at least 55MPH (again, not sure, not looking it up) to keep it in aero.
It should be speed activated. And frankly, it’s half an inch lower than standard.

8MPG is old V10 mileage days…lol.

Sure enough, it's on the window sticker, 3:21.

I'm most likely just jumping the gun, owning it for only a week. I'll mix in some random driving and see what the average is over the next month. Also expecting some mid-40's weather coming up.

I still haven't gone through all my settings, including the air-ride suspension, so not clear on the functioning logic of the "Aero" setting. All I know is I lowered the truck all the way down, it adjusted while I was driving to the second bar and the dash lit up as "Aero". I'll hopefully get a better understanding of this functionality soon.

Thanks again.

 

[OCD Solutions]

Curious if the previous owner had larger tires at some point and made any adjustments to the tire selection in the computer. 8.5 MPG seems very low, even for a "spirited" driver.

As a quick check, you could take a drive and see if the odometer matches what a map service says the route should be.

 

[Scram1500]

The gas is going somewhere, hopefully not into your crankcase. Fortunately the Hemi still has a dipstick so you can give the oil a sniff. Did you get to check the air filter and or intake yet?

 

[Richard320]

10 minutes idling every day, especially in extreme cold weather when it will be running extra rich on startup, will kill your fuel economy. In city driving, 10 minutes will get you five miles distance or more. Add 5 to your reading.

I live where it never freezes and if all I have been doing is short local trips with lots of stoplights, I will get 12.5 - 14 mpg. 5.7 and 3.21 gears, same as you. Throw in some freeway driving and mileage leaps up.

I don't think there's anything wrong with the truck.

 

[dajogejr]

Aero mode lowers the front end half an inch over 63 or 65 miles an hour. You can turn it off if you want, I never bothered.
You have to keep it above a certain MPH to keep it there.. I don’t recall the exact parameters, but I’m 100% certain it’s in the owners manual.
Or…you could watch this, I like simple..LOL
I honestly wouldn’t worry about the mileage. If I go on a long highway cruise and fill up my tank, it’ll tell me over 500 miles to empty.
I do a lot of remote start, city driving, and fill up my tank, miles to empty is low 400 range.
Go enjoy a nice ride..

 

[PurpleRT]

Just the wrong time of the season to really troubleshoot poor MPG, you have the elements going against you. Wait till spring time when the weather is nice and you’re back on regular fuel and go from there. Meanwhile enjoy your new truck don’t overthink it.


Sent from my iPhone using Tapatalk

 

[1923bob]

I'm excited to be part of the RAM community! I recently purchased a 2021 RAM 1500 Limited with 53K miles, and I’m absolutely loving the truck. Upgrading from a JKU, the difference in drive quality is night and day.

That said, I do have one concern regarding fuel economy. I fully understand that I bought a 5.7 HEMI with eTorque—it's a large, heavy, and not-so-aerodynamic truck that naturally consumes a lot of fuel. I’m not expecting the factory-rated 17 MPG city / 23 MPG highway, but my actual results seem unusually low.

According to the truck’s Avg MPG screen, I’m only getting about 8.2 MPG. To verify, I manually calculated after today’s fill-up and got 8.5 MPG.

Here are some details about my conditions that may help diagnose the issue:

• I did reset the trip computer after the dealership, knowing that test drives can produce low MPG.
• Outdoor temperature range over that past week has been between 0° - 12 ° in my area.
• I filled up with mid-grade 91 based on factory recommendations.
• I have eTorque start/stop activated.
• My ride height is at an efficient "Aero" setting according to the system.
• I'm driving in 2wd.
• This has been all local driving, I have yet to take it on the highway.
• I'm driving extra easy, just hoping to bump the MPG to prove myself wrong.
• I have been remote starting it in the mornings for about 10 minutes.
• 22" rims with standard all-season tires.
• No aftermarket engine upgrades or lifts.

I feel like the MPG is very low, and was expecting somewhere around 14 MPG city from this truck. Before posting this, I searched multiple threads for potential causes and solutions, but the answers range widely—from something could be wrong to just suck it up, it’s a pickup. As a first-time truck owner, I’d really appreciate any insights or advice on whether this is normal or if there’s something I should check. Any guidance would be greatly appreciated!

I get between 10-12 most of the time and I'm in Ca. I do have bigger tires.