Cummins fuel mileage

[MIMF]

OK Gents. Need some honest opinions. I have found 3 brand new Ram 1 ton duallys at our local Dodge dealer in Goshen. All 3 are very nicely equipped with ALL the goodies. Laramie packages, I think they are called. However, the info on the engines say they are 350 hp 650 ft lbs torque. For some reason, I thought they were rated higher than that and, they have the 3:42 rears. That is more horse and torque than my '05 Duramax LLY.

So, here's the question. Should I expect that the Ram will give me as good or better fuel mileage pulling the old Challenger as the Chevy? Currently, the Chevy gets me 12 or 13 mpg on flat open road with the cruise set at 63 mph and an average of 8 mpg in the mountains with the cruise set at the same speed.

What have most of you guys been experiencing?

[Ishler]

MIMF
My '11 gets 11-12 @65 on the flat 8 pulling through Penna. pulling our 3605 which is at about 14klbs it has the 4.10 gears. The new models are supposed to be better.

[woodtic]

350 hp / 650 ft lbs it think is the tuning for manual transmitions and the c/c trucks. Auto trannys are 800 ft lbs and the Aisin (sp) tranny is 850 ft lbs. From what I've read on the cummins forum, fuel milage won't be any better than your LLY. Maybe a little worse, but not much. I too have been looking a getting a new Ram 3500.

[Montana Sky]

I average 10/11mpg towing 16,400 lbs at 68mph on the flats. Have seen as low as 9 and as high as 13. The new Ram's will not get anywhere near the fuel economy you are used to with your Duramax. My last Chevy ran the same as you are seeing towing and upwards of 21/22mpg empty at 75mph. Best I have seen empty with my 3.73 dually is 17 mpg highway and that is a true rarity. Normal highway fuel economy for mine is 14/15 mpg.

[Sierra 117]

None of the new trucks will equal the mileage of your pre DPF Chevy, but the Ram will be competitive with the other new trucks.

[steelpony5555]

What ever you do do not change to larger then the factory tires especially with 3.42 rears. Don't ask how I know...lol lol lol... The Dodges are non programmable, meaning the old Dodges you could go in and change shift points and durations. The new Dodges are made so you cannot do that, the factory does not want you to change anything on them. I never thought changing a size or two in tires would have such a big effect on the towing power of this truck. The fuel mileage will be roughly the same when towing and will fall between 9-11 mpg. The biggest difference will be when running empty. If you don't plan on towing a lot the 3.42's would be fine for an around the town truck. But if you're gonna tow a lot the I would not drop below a 3.73 and would really want the 4.10 gears.. Just my opinion

[Ramblin Roadrunners]

Montana Sky, Its my understanding the 11"s and 12's did not get as good of fuel milage because they had an extra injector added to make it quiet and pass emission standards at the time. Yours is the last models without DEF and Dodge was tinkering and adjusting and doing all it could before changing to DEF in 2013.

[vangoes]

My '13 Ram 3500 SRW is getting 12+ towing, 21 empty highway and 18-19 combination empty city/highway. I have the aisin transmition and the 3:42 gears. I too was hesitant about the 3:42 gears but with the torque these vehicles have that gearing combination is perfect. Compared to my previous trucks with the 3:73 gears, this truck is a dream both power wise and fuel mileage wise. However, it does appear that I am using more DEF fluid than friends say they use with their Fords.

[Ramblin Roadrunners]

Vangoes, that is what I'm talking about. Some of the 11's do better than the 12's. Dodge was all over the place with computer mapping and trying to fine tune them.

[DQDick]

Once the truck got over 30,000 I get 11 towing and around 18 on the highway. If you have to stop at a traffic light, however, forget it. I think it uses a german beer stein instead of a fuel pump.

[CORattler]

Although I have a 2009 3/4 ton short bed, I can tell you don't buy the truck because of a 1-3 mpg gain/loss. The 6.7 Cummins LOVES to be worked and that is what it was built for. I tow a 15k rig, live in Colorado and go up & down the Rockies with no problems. I have 3:73 gearing and an auto transmission.
I will say that all the anti pollution junk they put on these trucks adversely affects mileage.
Best of luck to you no matter what you choose.

[Devildog]

I have the high output longhorn edition (850 torque) and 4:10 gears. Average 11 mpg pulling Montana, and get about 15 around town. Only 37,000 miles, so not broken in. And I have the Aisin transmission, automatic

[jlb27537]

quote:Originally posted by Devildog

I have the high output longhorn edition (850 torque) and 4:10 gears. Average 11 mpg pulling Montana, and get about 15 around town. Only 37,000 miles, so not broken in. And I have the Aisin transmission, automatic

Jim. my research tells me the 850tq/Aisin was only available in a '13 and up. If you have a '12 auto you have a 350/800 68RFE Mopar.

Unless you bought a cab and chassis then in '12 you could have a Aisin but the engine is a 350/800.

In a '13/14 a 350/660 is a 6 speed stick engine.

OP, on my '12 DRW 3.73 I get around 9-10 towing. 10-12 around town and 12-14 Hwy. But mine is not a daily driver only a tow vehicle. The '13 and up use DEF and they do get better mileage. None like to be short trip vehicles. They want to be worked and driving empty around town or on the highway empty just does not work them.

Crawl under it and see if you have a removable plate for a PTO mount on the front part of the tranny. A PTO plate = Aisin. No plate = 68RFE

Jim

[MIMF]

All good points to ponder on, guys! Very good input! After what you guys are saying and looking at and studying the window sticker, I may just back away from this truck. They have had it on their lot for awhile. It is indeed very nicely equipped with all of the things I would want. The price is very attractive for a 14000 lb GVWR. The window sticker shows it has the 68RFE tranny with 3:42 rears. It is DRW 4X4. That is another reason I may back away because, I really am looking at 3500 SRW which is all the truck I will ever need. However, I am learning that the GM 2500's have 10,000 lb GVWR compared to 9900 lb GVWR on this old '05 3500!! This '05 pulles the 14000 lb Challenger without any issues. But, I want to stay with a 3500 SRW because, even the new ones are at 11600 lbs GVWR. And, the pricing between the 2500 and 3500 is NOT that much different. Even if we do and I anticipate we will get a bigger and somewhat heavier 5th wheel in the future, the new 3500 SRW should handle one of those 16000 lb units just fine. On the other hand, I learned a long time ago, if the pricing is right and you get a good price for your trade, you never have too much truck which, still makes this Ram attractive! So, got more "pondering" to do.

[mhs4771]

Dale, that's how I ended up with our first Dually in 05. Was looking to order a 2500 D/A and Dealer had a new 3500 Dually with everything I wanted and made me a better deal than ordering. And we only had a 24' TT at the time.

[Hooker]

quote:Originally posted by MIMF

...Even if we do and I anticipate we will get a bigger and somewhat heavier 5th wheel in the future, the new 3500 SRW should handle one of those 16000 lb units just fine....

Could be, but I doubt it, I'd work the numbers. Our 07 D/A dually would have been over weight with a 16k 5th wheel. You can't believe the numbers the manufacturers post in thier literature.

Calculate the LOADED weight of the truck, including pin weight, and subtract that weight from the GCWR...and you'll have your towing capacity.

[rames14]

Dale, I was a loyal Chevy owner until I bought my '13 3500 Laramie Longhorn. That is the first year they offered the Aisin tranny. Aisin and Allison had a joint venture and both are medium duty truck transmissions. I only have 19k miles on it, but the early concerns from people on the 3:42 diff were unfounded. In fact, some that had to have the 4:10 are now having buyers remorse because of the loss of fuel economy and over torque. We went with SRW because of where we live in the mountains and how we use our truck. So far it has been a great truck. We also got the Mega Cab which allows me to throw shotguns behind the seat when I'm on a hunting trip. I would not hesitate to recommend the Aisin with the 3:42 on a SRW. If I got dually's, maybe the 3:73 would be a consideration. Good luck.

[Devildog]

My 2012 is the high output 850 torque, but has the 68 rfe tranny. Has pulled all mountains in Tenn , Colorado, Wyoming and Montana well. Sure do like the exhaust brake.
After 37,000 miles, highway mileage is rising well. Anywhere between 16 to 17. But I haven't run it on the highway solo that much.

[MIMF]

Ron, I do what to stay with a SRW for the same reasons you stated. It just works best for us. Wife has already stated that she is not crazy about getting a Ram. It all boils back to her experiences at her job she retired from last year. But, if I can show her that with a Cummins and a 3:42 rear, we will get marked improvement in fuel economy, there might be a chance of getting one.

And Jim, you are getting 16 to 17 mpg pulling the Montana? Tell me more!

[Devildog]

No, that is solo mileage. Average about 10.5 pulling overall. Came back from Colorado springs at the end of October and got 13 across the plains, but I had a very good tail wind!