Low MPG

[Seaeco]

Hello All,

New member here and I absolutely love my truck, but I’m curious to know if anyone else is experiencing lower than expected
in city or combined MPG. I currently have 1300 miles on the truck and know the engine is still breaking in, but I was expecting to see better initial numbers. Currently I’m averaging 15.2-16 with 80% city driving after 348 miles. I was expecting to be in the 19-21 range. Pure Highway mileage has been great with three separate trips, one from Idaho to Seattle I averaged 26.5, Seattle to Portland was 26.2, and the return 26.3. What are you all experiencing for primarily in city driving and any thoughts on my lower mpg? Perhaps a bad tank or winter fuel?

 

[JoeEcodiesel]

I have about 1500 miles and average 25-27mpg with about 85% highway

2020 Laramie Ecodiesel, Crew cab, 4x4, Level 2, Night Edition

 

[rorischak]

23 here in mixed 70% city 30% highway

 

[My1stHemi]

You’re still on factory oil and the engine is still new. Im not sure what the 4th gen eco diesels saw for break-in but I would check one of those forums. Hemi engines are seeing a break-in period of 5000mi minimum from my research and personal experience.
For reference I recently made the SEA to PDX run and got almost 10mpg less than you.

 

[CortC]

800 Miles, 3.92 rear diff, 33 gal fuel tank...

17-18 City
23-25 50% Combined
Highway is speed dependent:

65 Mph: 30-31
70 Mph: 29-30
75 Mph: 27-29
80 Mph: 25-27

All of the above is with a light easy throttle and maximizing coasting when possible. Just completed a 500 miles round trip with 90% highway on half a tank. Overall very happy with efficiency and performance of the truck.

 

[Seaeco]

Thanks for the replies so far. I'm going to change the oil in the next two weeks, which I do within the first 2000 miles on all my new vehicles, to see if that makes any difference along with the engine breaking in.

 

[My1stHemi]

800 Miles, 3.92 rear diff, 33 gal fuel tank...

17-18 City
23-25 50% Combined
Highway is speed dependent:

65 Mph: 30-31
70 Mph: 29-30
75 Mph: 27-29
80 Mph: 25-27

All of the above is with a light easy throttle and maximizing coasting when possible. Just completed a 500 miles round trip with 90% highway on half a tank. Overall very happy with efficiency and performance of the truck.

What type of terrain? Traffic? Those are impressive numbers!

 

[My1stHemi]

Thanks for the replies so far. I'm going to change the oil in the next two weeks, which I do within the first 2000 miles on all my new vehicles, to see if that makes any difference along with the engine breaking in.

You decide on oil yet?

Not sure if you have ever checked out “bob is the oil guy” forum. Those guys know how to geek out on oil specifications! It was thanks to that site that I researched oils best suited for my engine and discovered that using a moly additive in my synthetic oil has been shown to help prevent the “Hemi Tick.”

If I had more free time I could easily spend days learning about lubricants over there.

 

[VernDiesel]

Seaeco 3.21 on 20s? Might hurt in town mileage.

 

[Seaeco]

You’re still on factory oil and the engine is still new. Im not sure what the 4th gen eco diesels saw for break-in but I would check one of those forums. Hemi engines are seeing a break-in period of 5000mi minimum from my research and personal experience.
For reference I recently made the SEA to PDX run and got almost 10mpg less than you.

You decide on oil yet?

Not sure if you have ever checked out “bob is the oil guy” forum. Those guys know how to geek out on oil specifications! It was thanks to that site that I researched oils best suited for my engine and discovered that using a moly additive in my synthetic oil has been shown to help prevent the “Hemi Tick.”

If I had more free time I could easily spend days learning about lubricants over there.

thanks for recommending that site and I hadn’t thought about which oil yet. I was originally thinking to use what the manual states given how new the engine is, but now you’ve peaked my interest.

 

[Seaeco]

Seaeco 3.21 on 20s? Might hurt in town mileage.

3.92 on 20’s

 

[CortC]

What type of terrain? Traffic? Those are impressive numbers!

Live in Florida so no hills other than on ramps and overpasses, I avoid bumper to bumper traffic and keep a light foot. If I drive like I don't care (Heavier foot) the numbers drop somewhat to: 15-16 City, 21 Combined and 25 Hwy...

 

[Seaeco]

Hand calculation for my last tank: 466.1 Miles, 28.890 gallons used, 16.084 MPG, 80% city / 20% Hwy, normal driving, EVIC shows 16.4. I just filled up at a different station to see if the lower than expected MPG was due to poor fuel in the last tank.

I'm having my first oil change done this week at approximately 1,675 miles and I'll be using the Pennzoil Platinum Euro SAE 5w-40 that the manual specifies. I'll be curious to see how dirty the oil is or is not on this new gen 3 engine with this mileage.

 

[VernDiesel]

Bet it looks clean as new. You can pull your dipstick and run it across your finger and you will know.

 

[myles]

just over 3000 miles here, 3.92 gears

heavy city i get 16-18, like downtown LA traffic
light city going about 45mph with stop lights is about like 21mpg

with about 70% highway 30% city driving i am averaging 27 mpg

straight highway im getting 28-31 depending on how long i feel like crusing at 65-68 which seems to be the sweet spot

75mph+ milage drops kinda signicantly but seems to be getting better with more miles on the truck

 

[VernDiesel]

Myles what a great time we live in when we can get that kind of mileage out of a full size 4wd truck. And it’s no slouch and tows 1/2 ton appropriate loads fantastically well and fuel efficiently.

The economy of thats reads slightly better than my 4th gen 3.92 ED. But wait that is with both engine & transmission tunes. Power with my Tune equates 268 HP 465 TQ similar to the new truck as well. No cooling issues with this one and likely not the main bearing failures. I think Ram VM Motori hit this one out of the park.

Between the 5.7 3.6 & 3.0TD Rams got it covered.

 

[Big Red Rebel]

Myles what a great time we live in when we can get that kind of mileage out of a full size 4wd truck. And it’s no slouch and tows 1/2 ton appropriate loads fantastically well and fuel efficiently.

The economy of thats reads slightly better than my 4th gen 3.92 ED. But wait that is with both engine & transmission tunes. Power with my Tune equates 268 HP 465 TQ similar to the new truck as well. No cooling issues with this one and likely not the main bearing failures. I think Ram VM Motori hit this one out of the park.

Between the 5.7 3.6 & 3.0TD Rams got it covered.

Very well said

 

[StaceyR]

MPG is very dependent of driving style and speed. Diesels love the open road at reasonable speeds. My previous diesel, a Jetta SportWagen, would return 45+ MPG at 65 on the freeway but dropped to low 20's in city unless babied. 15 to 20 MPG in city driving would be an improvement over my current Ford EcoBoost 3.5L. 25+ MPG on the highway would be sweet!

 

[Seaeco]

Just filled up and my last tank breaks down like this. 50/50 City/Hwy - 554 miles driven, 30.049 gallons used, 18.437 MPG hand calculated. EVIC was showing 17.9 so I was pleasantly surprised the MPG was better. I'm starting to realize that many of the higher MPG responses on varying forums are likely in flatter areas versus where I live. City driving also affects my MPG more than I thought it would, but at the end of the day, the overall mileage capability of this truck is outstanding. I absolutely love my truck and now if I can find a good local service center.

 

[MF2020]

Hello All,

New member here and I absolutely love my truck, but I’m curious to know if anyone else is experiencing lower than expected
in city or combined MPG. I currently have 1300 miles on the truck and know the engine is still breaking in, but I was expecting to see better initial numbers. Currently I’m averaging 15.2-16 with 80% city driving after 348 miles. I was expecting to be in the 19-21 range. Pure Highway mileage has been great with three separate trips, one from Idaho to Seattle I averaged 26.5, Seattle to Portland was 26.2, and the return 26.3. What are you all experiencing for primarily in city driving and any thoughts on my lower mpg? Perhaps a bad tank or winter fuel?

I love mine too but it appears we have similar equipment and I am averaging 12.5 MPG city and about 16.5 highway. I would be thrilled to get the mileage you get. LOL