5.7 with 3.21 Rear Axle in 2021 Limited Gas Mileage ?

[1923bob]

My 2021 gets about 10.5 average and I don't drive crazy Is this about right? 4,149 miles on it so far.

 

[Dewey]

That’s terrible.

I drive mine hard and still average just over 16 mpg even with a lot of 80 mph freeway driving. If I take it easy 19-20 mpg is easily attainable. Been like that since my first tank when new and approaching 7000 miles now. Worst I’ve seen while towing my boat was 14 mpg. Been exactly the same with my last 3 Hemi’s and 3.21’s.

 

[mikeru82]

Agreed, 10.5 mpg is terrible. When I had my '21 Limited with the etorque Hemi, my combined mileage was about 15 mpg in winter and 16 mpg in summer. And I thought that was bad. My city/highway driving mix was 20% city, 80% hwy. I have no idea what kind of mileage the wife gets with her '20 Limited LOL.

 

[Richard320]

That's pretty bad. However, it's still not even broken-in. My mileage improved quite a bit after the first oil change at 5,000 miles.

It sounds like you might do a lot of very short stop-n-go trips, which is going to kill your economy. You have to feed all 8 cylinders at idle, and they are extra hungry before they get warmed up.

Fill the tank, zero everything, then go for a nice leisurely drive out to Julian for some pie, using the cruise control and keeping it below 65. Bet you get better than 20 mpg then.

 

[LakesAZ]

Even with my 3.92 rear end I'm getting on the average 16.50 in the city and just about 20 on the Highway. Overall I'm at 17.75 with 12,000 plus miles and that includes towing.

 

[jl13]

that is normal for city and short trips.
That is my average if I only do city driving. maybe goes up close to 12 at times
Highway is 17-20 depending on the speed

 

[jkm312]

It does sound lower than it should be, but you still have a green engine. Mine finally got significantly better around 12, 000 miles. Traffic in Poway can be a mixed bag. My son was stationed in San Diego and I had a good friend live in Poway. Some more details about how your truck is set up may give us a better idea of what to tell you. Tires, tire pressure, what kind of gas you have in the tank, AC and driving style all have some influence on gas mileage. I average around 15, 18 or slightly better at 70 on the highway. On a windy day or I stick my foot in it, then that's another matter.

 

[theblet]

Don’t remote start your truck or let it idle for long periods of time. This kills mpg. It should improve after break in. I have 33” tires now and still make 16 to 18 avg with city driving.

 

[WXman]

Been tracking mine by hand so far with a little over 2,000 miles on it I'm seeing 17 MPG combined, 16 MPG combined if I use my small utility trailer one day per week. Pretty much spot-on what the window sticker said it would get.

 

[Buz]

As @jl13 pointed out, 10.5 is not too far off normal if you do lots of short trips that don't allow your engine and all it's components/fluids to come up to full operating temperature. An engine is LEAST efficient when it's 'cold'. When your oil is up to 215 degrees and your transmission fluid is up to 185 degrees it's only then that your engine will return it's best mileage for any given speed.
I do a lot of short, under 7 mile, trips and rarely get above 12 or 12.5 MPG.

 

[Amazing93]

Another thing to remember is Limiteds are pigs. They weigh a lot with all the extra doohickies they have.

 

[1923bob]

That's pretty bad. However, it's still not even broken-in. My mileage improved quite a bit after the first oil change at 5,000 miles.

It sounds like you might do a lot of very short stop-n-go trips, which is going to kill your economy. You have to feed all 8 cylinders at idle, and they are extra hungry before they get warmed up.

Fill the tank, zero everything, then go for a nice leisurely drive out to Julian for some pie, using the cruise control and keeping it below 65. Bet you get better than 20 mpg then.

Good idea drive to Julian for some pie

 

[1923bob]

As @jl13 pointed out, 10.5 is not too far off normal if you do lots of short trips that don't allow your engine and all it's components/fluids to come up to full operating temperature. An engine is LEAST efficient when it's 'cold'. When your oil is up to 215 degrees and your transmission fluid is up to 185 degrees it's only then that your engine will return it's best mileage for any given speed.
I do a lot of short, under 7 mile, trips and rarely get above 12 or 12.5 MPG.

Ya lot of short trips. Did go to Denver when we got it and it was not bad.

 

[2021Reglimj]

As @jl13 pointed out, 10.5 is not too far off normal if you do lots of short trips that don't allow your engine and all it's components/fluids to come up to full operating temperature. An engine is LEAST efficient when it's 'cold'. When your oil is up to 215 degrees and your transmission fluid is up to 185 degrees it's only then that your engine will return it's best mileage for any given speed.
I do a lot of short, under 7 mile, trips and rarely get above 12 or 12.5 MPG.

At 8k on my 2021 i am at 14 town and 23 on the long drive. Still a big swing. But lots of factors involved in the calculations too. I burn 87oct, because Costco dose not sell 89oct here. $5.45/gal for 87.

 

[GSD-STS7]

I hand calc’d my Laramie for about 10k miles. I noticed no difference in 87/89/92 octane. I averaged 17.5 with all my driving over those 10k miles. Worst tank ever was about 9 when I went about half a tank on trips all less than 5 miles each direction. I can get low 20s when doing 50-60 mph. Those numbers are with 33” Falken Wildpeak AT3W

 

[Hackmunch]

3.21 with 33at tires. 63k miles. lifetime mpg is 20.1mpg. most is freeway driving though. also i have mds disabled.

 

[Fishman]

My 2021 gets about 10.5 average and I don't drive crazy Is this about right? 4,149 miles on it so far.

Freeway. 20. around town. 15

 

[Marty313]

My 21 gets 12-13 with e torque and 35’s.

 

[Av1]

You can greatly improve fuel economy in these Rams by how you drive. It's not about driving slowly, but driving efficiently, in my opinion. Those are two very different ways of driving.

My wife drives slowly everywhere she goes and gets horrible fuel economy in any vehicle she drives.

It's pretty common for folks to get 20+ mpg in the Hemi Rams when doing freeway driving.

My driving so far has been about 70/30 city/hwy just for reference.

 

[theblet]

I normally do a “brisk” acceleration, where the trans shifts around 3k rpm. Then set the cruise when I get to the cruising speed. (Obviously not city driving)

I find it’s better to make 3 mpg for 5 seconds, than 5 mpg for 15 seconds(slow acceleration)