Ram 2500 5.7 hemi mpg.....a bit disappointed

[zogg]

The other day we took a trip ftom southern illinois, through st louis, to southern Missouri...a couple of hundred miles each way.

Starting out I reset the mpg meter on the dash, and recorded 17.4-17.8 mpg driving at 62-65 mph going through st louis. Once we got out of town, I ran at 75 mph the rest of the way to our destination. The MPG continually dropped until it hit 14.3, which is where it stayed.

Going through southern Missouri is fairly hilly and the truck geared down quite often...more than expected.

On the return trip, I again reset the mpg meter and after about 30 miles at 75 mph, I was right back to 14.3 mpg.

A we approached st louis, we had to slow back down to 65 mph.....mpg came back up to 17.3 and we finished the trip at 17.6.

I never had a truck that would drop 3+ over a 10 mph range....surprising. we were totally unloaded in 2wd the whole trip. 

I am wondering how this compares with the 6.2 L engine in the same truck??????

I was kind of expecting about 3-5 mpg better from the 5.7 hemi

[spoon059]

My 4x4 Tundra has a 5.7. Not the same engine, but similar HP and torque. The Tundra is also quite a bit lighter than a 2500 Ram. Best I have ever gotten was 18 mpg going to the beach at about 68-70 mph unloaded. That was on flat ground, highway with minimal traffic. My RPM's never get above 1800 or so... but it takes a good amount of power to push a brick through the air that fast.

I average about 15, but that is with a lot of city-style driving. I might see 5-10 miles on the highway, but spend a light of time either speeding up or slowing down with all our traffic lights.

I think your numbers are pretty decent for a heavy truck and high speeds. Honestly the 6.4 might give better or equal mileage because of the weight of the truck. The 5.7 might need to wind up a little more to keep moving, whereas the 6.4 doesn't need to work quite as hard.

The 5.7 is a good engine and should last you a long while though. Think of how much $$$ you saved versus buying a diesel. That will buy a LOT of gasoline!!!

[eichacsj]

zogg wrote:
I was right back to 14.3 mpg.

14 MPG with towing a 34' trailer? I'll take it :-). I have a AF 30U (very heavy) towing with a 2500 HD 8.1, I get 8 - 10 MPG depending on speed, wind, hill variables.

I don't think you will get much better no matter what you have.

[colliehauler]

Another thing to keep in mind is winter blend fuel will not produce the same mileage as summer blend.

[p220sigman]

Heck, I'm jealous. When I had my '06 Mega Cab, I never got over 14 regardless of how I drove it.

[gcloss]

I have a 2012 Ram 2500 with the 5.7 Hemi, 6-spd auto and 4:10 rear. If I'm going down hill with a tail wind, a full moon and all of the stars are aligned I'm lucky to get 16.5 mpg @ 65 mph.

I chalk it up to that's what it takes to move a 3-1/2 ton truck.

[4X4Dodger]

zogg wrote:
The other day we took a trip ftom southern illinois, through st louis, to southern Missouri...a couple of hundred miles each way.

Starting out I reset the mpg meter on the dash, and recorded 17.4-17.8 mpg driving at 62-65 mph going through st louis. Once we got out of town, I ran at 75 mph the rest of the way to our destination. The MPG continually dropped until it hit 14.3, which is where it stayed.

Going through southern Missouri is fairly hilly and the truck geared down quite often...more than expected.

On the return trip, I again reset the mpg meter and after about 30 miles at 75 mph, I was right back to 14.3 mpg.

A we approached st louis, we had to slow back down to 65 mph.....mpg came back up to 17.3 and we finished the trip at 17.6.

I never had a truck that would drop 3+ over a 10 mph range....surprising. we were totally unloaded in 2wd the whole trip. 

I am wondering how this compares with the 6.2 L engine in the same truck??????

I was kind of expecting about 3-5 mpg better from the 5.7 hemi

I have a 2014 Dodge Ram 2500 4x4 short bed with a 5.7L and I get right at 15 (14.9 to be exact)Highway. Now this is what the trip computer says. but if you figure the MPG by doing the math on what you put in the tank and miles driven it will be different. My Fuel Buddy App on my phone (which is great by the way) tells me this:

Overall city and hwy avg = 12.9mpg
and my cost per mile is= .179

If you are getting 17mpg you are doing really well.

If I drop down to 60 MPH I can increase the MPG to about 17 (NOT Towing)

So it seems that your mileage is about the same as mine. This is a BIG truck and its heavy and displaces a lot of air. You just cant move that for free. Also the big Hemi is not made for fuel economy. But its a great engine.

Look into that Fuel Buddy App its great. (and it is one of the few apps that does not want access to your phones/email contact list which is an important consideration when downloading free Apps)

[mayo30]

zogg wrote:
The other day we took a trip ftom southern illinois, through st louis, to southern Missouri...a couple of hundred miles each way.

Starting out I reset the mpg meter on the dash, and recorded 17.4-17.8 mpg driving at 62-65 mph going through st louis. Once we got out of town, I ran at 75 mph the rest of the way to our destination. The MPG continually dropped until it hit 14.3, which is where it stayed.

Going through southern Missouri is fairly hilly and the truck geared down quite often...more than expected.

On the return trip, I again reset the mpg meter and after about 30 miles at 75 mph, I was right back to 14.3 mpg.


A we approached st louis, we had to slow back down to 65 mph.....mpg came back up to 17.3 and we finished the trip at 17.6.

I never had a truck that would drop 3+ over a 10 mph range....surprising. we were totally unloaded in 2wd the whole trip. 

I am wondering how this compares with the 6.2 L engine in the same truck??????

I was kind of expecting about 3-5 mpg better from the 5.7 hemi

What size tires you running?

[mtofell1]

75mph is tough to get good mpg with any vehicle. Also, LOTS of factors that could explain poor mpg on one trip. Wind would be the main one. Expecting 3-5 mpg better? Did you really expect 17-19mpg while going 75 in a HD gas truck?

[Bionic_Man]

Looks like you experienced MPG ranging from 14 - 17. What was the average for the entire trip? Was that from the computer readout, or hand calculated? Reason I ask is that I have two vehicles where the readout is just about dead on, and two that are off (in both directions).

Just curious where you came up with your expected numbers? Did you come from another HD truck, or is this your first?

As others have stated, MPH has a big effect on MPG. As a point of reference, the few trips that I have taken my truck unloaded on the highway, I get around 14 MPG cruising between 75 - 80 MPH.

The easiest way to get better MPG is to slow down. You might get around 20 MPG at 60 MPH. Have to decide, which is more important on the trip, MPG or time?

[fla-gypsy]

The results were very normal. In my 6.8L/4.10 SD I struggle to reach 16 pn the highway and average about 12 around town in mixed driving. Best highway economy is between 60 and 65mph.

[fla-gypsy]

BenK wrote:
What trailer tires?

If ST, note that they are rated for a MAX of 65MPH

Ben he wasn't towing anything. He stated the truck was unloaded.

[mabynack]

Cummins Fuel Economy Guide

Here's a guide that Cummins put out to explain factors that impact mileage. There's a good explanation of the effects of aerodynamic drag. Aerodynamic drag is not a linear function of air speed. Drag rises pretty sharply after 50 mph. Your speed and any headwind or tailwind can really impact how hard your engine has to work to keep you at speed.

[mabynack]

My mileage drops off quickly above 60 mph. I'm not surprised at your findings.

[phillyg]

That's a big truck with 3.73 gears and driven in winter with who knows what in the gas formula so I'm not surprised.

[BenK]

What trailer tires?

If ST, note that they are rated for a MAX of 65MPH