5.9 vs 6.7 mileage

[1971]

We're trying to decide on whether to buy the 2011 3500 6. 7 Megacab 4x4. We have a 2006 3500 5. 9 Mega 4x4. Same truck right down to the color. One question that we can't seem to get a straight answer on is what we can expect for mileage. Is there anyone out there that can give me some numbers?

 

[Simplysmn]

well Just bought a 3500 srw truck yesterday and on the drive home {160} miles it was showing a average of 14. 6 so I would say after breakin time you should see that also

as you put miles on it the fuel economy will come up

 

[EGroeneveld]

Brand new truck I ordered and then recieved last Tuesday At lunch today, Mile 329 filled up with 29. 41 gallons at 3. 43/gallon for $ 100. 87 total. 11. 1 MPG, which matches the Economy gauge report perfectly.



Note when I picked the truck up it had 15 miles on it and the fuel gauge was reading past the full mark. Don't know if they topped it off or not. I always top off and was able to add a few more bucks today.



Miles are mixed, one 80 mile round trip on backroads from Keizer to Newberg, mostly in town Salem/Keizer area with some 5 mile runs on the freeway. 30 miles of the tank I was pulling an enclosed trailer that weighs about 8k pounds.



2011 3500 6. 7 Ram Dually 4*4 Laramie 4. 10 gears.

 

[EGroeneveld]

My old 2005 Ram 3500 Dually 4*4 Laramie with 3. 73 doing the same mix of driving always seemed to get 15ish. I could get 20 on a highway run not towing and running empty close to the speedlimit (OR is 65 and WA is 70). The 2005 was a Quad Cab, the new truck is a CrewCab.

 

[MChrist]

If they are both identical models, I would assume they are both manual 6 speeds with same rear axle ratios? If your rpms are the same at say 60 mph, then my understanding is that the newer model will give slightly less distance per gallon, due to all the emission equipment on the new model. Exact numbers, I don't have. . sorry. I'm sure several people with newer models will chime in very soon to give you what you are looking for.
Welcome to the forum!

 

[Tryingit]

My 5. 9L got just about 21mpg on the highway (with a Smarty Jr, exhaust and intake system)). I have yet to hit 18mpg on the highway with my stock 2010. I hoping to improve with more mileage. But I doubt I will get 21 mpg with this truck. But the up side is that it (2010 stock) easily out tows my 04. 5 with the add on's.

 

[1971]

Automatics. 373 rear. Thanks for the welcome mat. It's been crazy listening to these salesmen who I swear must drive Hondas. They are so clueless it's funny. We really want the new truck but with all this talk about $5 a gallon fuel, we're worried about how much less we're going to get a gallon. We've got a Hypertech and we're getting 12-13 in town (ideling at the school in car line doesn't help) and somewhere around 18-19 on the highway empty. We live in Florida so it's all flat except for the Skyway.

 

[EGroeneveld]

I'll add my 2011 pulls the same trailer much easier then the 2005.



Also both the 2005 with 3. 73 and 4 speed auto and the 2011 with 4. 10 and 6 speed auto seem to do 2,000 RPM's at right around the same speed of 72/73 MPH.

 

[1971]

Is it flat or mostly hills where you are?

 

[HBarlow]

Salesmen only lie when their mouths are moving.

Everyone's fuel mileage is a little different, no one can tell you exactly what your fuel mileage will be.

I think it is fair and honest to say that a new Ram with 6. 7 will get approximately 1 or 2 mpg less than a 5. 9 with identical driver and operating environment.

If you want the new truck don't let the fuel mileage be the deciding factor.

 

[1971]

Considering the cost, I'm trying to take many factors into consideration. I really don't want to be freaking out over a huge loss of mileage after I shell out big bucks for a new truck. I'm now trying to decide between getting another silver one or try the deep water blue.

 

[lil red cummins]

The one item not mentioned here is the EPA mandated polution controls on the newer models. With the extra fuel used by post combustion injections and "regen" cycles that the DPF require (just to mention a couple mileage busters), I can't see how an 2007 thru 2011 truck is ever going to get equal or better mileage than any pre 2005 truck.

I am glad that i bought mine in 2003 (04. 0 model) as it gets 20 average running around town. This is hand calculated in my log book. It is driven almost always empty and used as a daily driver.

I would imagine that heavy towing would probably not yield that much difference from new to old versions, so it depends how you plan to use it.

As the gas engine version of these trucks continue to get better mileage at the same time that the diesel drops in mileage, the justification for this truck is more difficult.

If you plan on putting 300,000 miles or more on you truck, then it will still be a good deal.

Just my . 02

Jim

 

[rscurtis]

Don't overlook resale value in your calculations. See what a 2003 with a Hemi is worth compared to your '03 with the Cummins.



The gas engines in the half tons are improving in FE, but there isn't much improvment in the HD series, espescially if the truck is used for any kind of work. I believe Ford has the bragging rights to that right now with their new "Boss" engine.

 

[RustyJC]

With just over 2K miles on our truck, I don't have long-term mileage figures, but so far it looks like we're getting around 16 MPG unloaded on the highway and 9. 1 or so MPG towing the 16,000 lb RV in my signature. My BOMBed 2002 HO/6-speed with 4. 10s got 9. 5 to 10 MPG towing the same RV and 17 MPG or so running unloaded on the highway. My previous V-10/47RE/3. 54 dually got about 6. 5 MPG towing our previous 13,500 lb 5th wheel RV, so even with the lower fuel mileage than our previous diesel, our 2011 is still head and shoulders above a gasser for our application before the superior power and torque characteristics of the diesel are even considered.



Rusty

 

[Alan Reagan]

I am averaging 15-16 for my daily 40 mile round trip for work and 17-18 on the highway with the cruise set aat 70. I'm 2wd and I'm sure that helps. It was a shock after getting 22 mpg on my 05. But it was a 2500 and this is a 3500.

 

[sag2]

Just took a 2010 auto 1,600 mile round trip SF to Portland with a 28' trailer. Empty going up, loaded coming home. Loaded was probably not over 6,000 lbs. Ran 4 over the posted speed (59 in CA, 69 in OR) with the cruise on and averaged just over 10. 5 mpg for the whole trip. Several hundred miles truck only. Truck had 2200 miles on it when I left.

With my neighbors 06 5. 9 auto pulling the same trailer with more weight CA to CO at 75 most of the time we averaged 6. 8 for the trip. I have to say speed is the biggest factor as the CA portion was averaging 2-3 mpg higher at the lower speed, and way more than that when you were going 75-79 mph.

 

[MChrist]

Sag2, you said you got 6. 8 for the trip... didn't you mean 16. 8???

 

[SOLER]

You're not going to get as good of mileage. I am about to get rid of my '10. I hate the mileage. One of the arguments and benefits of a diesel used to be mileage. More power and better mileage than a gasser.



Well, now-a-days, power (but not by much of a margin anymore) is still there, but mileage is out the window. Towing with a diesel vs a gasser, I think a diesel still wins in power and fuel economy, but when empty, I want a gasser. I hate getting 12-13, no matter what I do. City and highway stays right around 12-13. If you want the mileage, get an older truck. I wish I still had my 2001. 5 that got 17-21 MPG, and 12-13 when towing our big 5er. Those days are over



SOLER

 

[sag2]

Sag2, you said you got 6. 8 for the trip... didn't you mean 16. 8???

Six point eight. Speed kills fuel economy.

 

[MChrist]

I was hoping that was a mis-print. I am very diligent (freaky) about monitoring my fuel mileage, and the lowest hand calculated tank I ever got was 11. 53 mpg. I, too was traveling 75 mph, towing our 30' Jayco. When I drive 65, I'm around 12. 5 to 13. 5, depending on headwind.
I've read many of your posts, and you seem to have way more mechanical knowledge than me, so do you think something may be wrong to give you a 6. 8 reading? Or were you traveling uphill, both ways, into a 60 mph wind?