Towing with gas vs diesel

[Surgdoc4]

Admittedly I am a diesel guy, I tried to go to gas but the dark side drew me back. Had diesels for 20 years then decided I didn’t need that much of a truck and bought a half ton gas and an all aluminum 14 ft trailer. Even that was like pulling a parachute and lucky to get 10 mpg. That truck didn’t last long. Back to diesel. If buying a truck for pulling a large RV why gas? What am I missing? I have a 2500 6.7 SRW and a 3500 6.7HO DRW on order. Please explain why I should order a 3500 DRW with a 6.4 Hemi. Now have a 15k (dry)RV toy hauler to pull. thanks

 

[kevin588127]

For me, only about 15 percent of my usage is towing and I don't want to put up with the diesel the rest of the time. I don't want the added maintenance. I don't want the initial expense. I don't want def and it's potential problems. I don't want to delete. I've done the math on the fuel mileage and it is basically a wash. This all works for me as I am only towing in the 10k range and not very often. If I were towing the 15k range or doing it more, I'd get the diesel.

 

[TinGoatTravelers]

Admittedly I am a diesel guy, I tried to go to gas but the dark side drew me back. Had diesels for 20 years then decided I didn’t need that much of a truck and bought a half ton gas and an all aluminum 14 ft trailer. Even that was like pulling a parachute and lucky to get 10 mpg. That truck didn’t last long. Back to diesel. If buying a truck for pulling a large RV why gas? What am I missing? I have a 2500 6.7 SRW and a 3500 6.7HO DRW on order. Please explain why I should order a 3500 DRW with a 6.4 Hemi. Now have a 15k (dry)RV toy hauler to pull. thanks

You shouldn’t. I tow a 7K trailer loaded for camping. Used to tow with a diesel. Got the Ram 2500 6.4 Hemi. I wouldn’t tow much more than mine with this truck. At 15K, if it was my decision, even if only towing 10% of the time, I’d go diesel with all its frustrations 100% of the time.

 

[Lerker]

Advice for not just you, but anyone deciding between gas and diesel:

Understand your needs, then buy the appropriate tool.

In your case, you absolutely need the diesel. No question.

The gasser makes sense if you're predominantly hauling. It'll tow lighter loads in flatter terrain, too. When the trailer gets heavier and/or the terrain gets higher, a diesel is the way to go. Easy.

 

[Firebird]

It's all about preference. I bought a 2019 2500 with the 6.4, and I really liked the truck a lot. It drove well, was comfortable, it towed my camper pretty well too, more effort than a diesel for sure, and lots of gear changes, but it could do the job.

Dealer wanted my 2500 real bad, and made it worth my time to trade out to my current 3500 DRW Cummins. As much as I liked my 6.4, my 3500 does everything better. It tows easier, it rides almost as good, gets 50% better economy towing, doesn't hunt gears, and you really can hardly tell the camper is even back there. The stability factor is just amazing.

That being said, I do like the 6.4 very much, but the 6.7 just does everything so much easier

 

[Grey65]

I have a 30ft 5th wheel trailer that weighs about 10k and is 12 feet high.
I had a 2020 Ram 2500 Laramie 4x4 with the 6.4L.
I now have a 2022 Ram 2500 Longhorn 4x4 with the 6.7L.
Both towed trailer without an issue, the 6.4L would hunt gears but would never slow down. With the 6.7L you do not know the trailer is there. But both work fine....

6.7L Advantages:
1. Getting fuel with a 6.4L when towing a 30 foot trailer can be a pain whereas getting fuel with a 6.7L is not an issue as you can use big rig lanes.
2. Can go further on a tank with the 6.7L.
3. Can add a gravity feed AUX tank with the 6.7L, which means you can go even further on a tank.
4. 6.7L has an exhaust brake, which if you tow in the mountains is really nice.
5. Much better MPG's when not towing.

6.4L Advantages:
1. Higher payload.
2. Cheaper buy-in.
3. Cheaper oil changes.
4. No DEF required.
5. Don't have to worry when wife put gas in tank instead of diesel.

 

[WXman]

Well yeah, if you're going to be dragging a 15,000 lb. camper around then go for the most torque you can get. That's a no-brainer.

For MOST people, however, the diesel doesn't make any financial sense at all. The Hemi will tow great, is much easier to maintain, has no finnicky emissions system to worry over, has no $10k fuel injection system to worry over, is $10k less to buy up front, and runs on fuel that's currently $1.10/gallon less. Using real world owner data from Fuelly, we see that the Hemi averages about 13 MPG and the Cummins about 16 MPG. At current prices, assuming 1,500 miles per month driven, the Cummins will actually cost $54 MORE per month in fuel. There's just way too much cost and way too much hassle associated with the diesel. Guys buy them because it's a status symbol, but most would be much better off with the gas engine.

I really wish Ram would revamp the 6.4 to more closely compete with Ford's 7.3. That's the cat's meow.

 

[dieselscout80]

Ford also had the 4.30 axle ratio that would help the 6.4.

 

[raven_dt]

Admittedly I am a diesel guy, I tried to go to gas but the dark side drew me back. Had diesels for 20 years then decided I didn’t need that much of a truck and bought a half ton gas and an all aluminum 14 ft trailer. Even that was like pulling a parachute and lucky to get 10 mpg. That truck didn’t last long. Back to diesel. If buying a truck for pulling a large RV why gas? What am I missing? I have a 2500 6.7 SRW and a 3500 6.7HO DRW on order. Please explain why I should order a 3500 DRW with a 6.4 Hemi. Now have a 15k (dry)RV toy hauler to pull. thanks

15k dry Toyhauler is diesel territory imo, especially for the exhaust brake capability. If you wanted a gas option I would look into the Ford 7.3.

 

[raven_dt]

Ford also had the 4.30 axle ratio that would help the 6.4.

The 7.3's torque curve is flat like a diesel coming on strong at 1600rpm (80% of max torque available at 1600rpm). The 6.4 just can't match that torque curve. We towed our 36ft TT (11.5ft high x 8ft wide) back from the Keys this weekend and the 6.4 was solid. It held 65mph over 2 days without issue. I stayed in 5th and 6th gear almost the entire trip, that rpm isn't conducive for good mpg. Having said that, we did get 8.4mpg (hand calc) over the 1200 miles, not bad. We had a couple of downshifts to 4th resulting in short stints into the 4100rpm range. Ford's 10 speed also has 3 ODs vs the 2 OD in the ZF transmission. The 8HP75 is a superior transmission. The 6.4 will get the job done, but it's not a 6.7 replacement.

 

[BaseBD]

They all said it right. I had a big 5th wheel and towed with a 6.7 powerstroke and it was great. Moved to a truck camper and a car trailer. Liked the extra payload and simplicity with the gas engine. Haven't done the mountains but went through northern Wisconsin/UP at 20K lbs without issue. No long grades but plenty of smaller hills at 6-8%.

 

[tchur1]

If you ask this question to 1000 people you are going to get 1000 different opinions on why one is better than the other. So as someone on the internet that you have never met I look at it in terms of 1) Use case 2) Cost

Its really easy to justify the gas when looking at it only financially, its cheaper to buy and cheaper to maintain, and the MPG gains take a long time to even that out.

BUT individual use case is more important IMO, and anytime you are towing over 10k pounds I think diesel is the answer. The whole experience is just so much easier/more controlled, and if thats valuable to you then it makes it easy to eat up the difference in cost

If I were you Id be getting a diesel and not thinking twice. I live in the mountain at about 6800 feet so NA engines lose a lot of power here. My cummins pulls our 10k boat around up here like its not even hooked up, and the exhaust brake makes descending mountain passes brainless. Ill never go back.

 

[Redfour5]

Well yeah, if you're going to be dragging a 15,000 lb. camper around then go for the most torque you can get. That's a no-brainer.

For MOST people, however, the diesel doesn't make any financial sense at all. The Hemi will tow great, is much easier to maintain, has no finnicky emissions system to worry over, has no $10k fuel injection system to worry over, is $10k less to buy up front, and runs on fuel that's currently $1.10/gallon less. Using real world owner data from Fuelly, we see that the Hemi averages about 13 MPG and the Cummins about 16 MPG. At current prices, assuming 1,500 miles per month driven, the Cummins will actually cost $54 MORE per month in fuel. There's just way too much cost and way too much hassle associated with the diesel. Guys buy them because it's a status symbol, but most would be much better off with the gas engine.

I really wish Ram would revamp the 6.4 to more closely compete with Ford's 7.3. That's the cat's meow.

Keep your eyes open for the new engine the inline six gas or other fuels...based upon the Cummins. It seems like a distinct possibility...

 

[raven_dt]

Keep your eyes open for the new engine the inline six gas or other fuels...based upon the Cummins. It seems like a distinct possibility...

I'm hoping for a large displacement, simple (no turbo, no mds, no auto stop start) V8. That is looking more and more like a pipe dream... I saw the larger displacement hurricane engines and the rumored Cummins 6.7 gas. Give me a large displacement simple V8 engine...see Ford 7.3.

 

[Firebird]

I'm hoping for a large displacement, simple (no turbo, no mds, no auto stop start) V8. That is looking more and more like a pipe dream...

With this insane push for EV by the government, you have to wonder how much new development will happen on gas V8's? I wonder if they will all soon go the way of the dinosaurs

 

[raven_dt]

With this insane push for EV by the government, you have to wonder how much new development will happen on gas V8's? I wonder if they will all soon go the way of the dinosaurs

Yep, but with current 100 mile range towing that's a ways off for most folks.

 

[Redfour5]

I'm hoping for a large displacement, simple (no turbo, no mds, no auto stop start) V8. That is looking more and more like a pipe dream... I saw the larger displacement hurricane engines and the rumored Cummins 6.7 gas. Give me a large displacement simple V8 engine...see Ford 7.3.

Then the 7.3 is going to be your only choice is my thought. It may be the last of the V8 NA beasts...

 

[gimmie11s]

I love when the argument of gas vs diesel comes down to "fuel cost". I guess they forget that you will need to spend 65-75 THOUSAND dollars on the truck to begin with regardless of fuel type.

Hilarious.

My advice to "those" guys: Buy a $5000 1997 big block, manual trans (for maximum efficiency!) Chevy. Install Adance Adapters Ranger gear splitter along with 4.56 axle gears. Yeah, you'll need to split every gear on every shift just to keep the load moving, but hey...

Now you can tow 20k lbs on the cheap while proclaiming you can "do it with a gas truck". You'll be laughing all the way to the bank!

 

[troverman]

I'll give a little different perspective. I have a 2019 RAM 3500 SRW HO Cummins / Aisin and now a 2022 RAM 2500 6.4L Hemi. The 8 speed is just such a better transmission than the Aisin. Not as heavy duty but so much better in terms of performance. The Hemi truck is rated to tow 14,700. I have towed nearly all that with a 30' gooseneck and tractor / shredder combo. There's no doubt the Hemi is working very hard. But it was never a case of not enough power to make it up a steep hill, etc. The diesel doesn't rev as high, but it surely isn't "fast" and at this weight you can certainly tell its working. Bring up the turbo boost gauge and you can see its working. Without a doubt, the Cummins pulls that much weight with more confidence, and better fuel economy. Empty, I find the diesel is only getting 1-2mpg better on the open road than the Hemi. That tradeoff isn't worth it given the price difference with the fuel.

Now, regarding the OP's question about the dually and his 15k trailer: I would go with the diesel without a thought. Nobody buys a gas dually unless they are in some unique situation of needing massive payload. The added dually weight makes fuel economy even more miserable, and resale value is in the tank. For a tall, heavy trailer...dually is the way to go. But 15k isn't really all that heavy. I've towed 30k with a 2017 F-350 dually (diesel). Now that's heavy, and it requires a CDL.

If you like the gas V8, the Ford 7.3L as others have mentioned is the way to go. Very simple pushrod engine, port fuel injection, no cylinder deactivation, etc...very understressed. The Ford will have cheap oil changes. The Hemi requires 0w40 synthetic oil which is not that cheap. Better than a diesel, but not cheap.

 

[pizzatots]

Im going 2500 6.4 for:

-Extra payload (planning to tow my 30ft tt and have no worries if we want to bring dirt bikes)
-Cheaper, easier to find fuel
-No emissions stuff
-Owned a 1500 eco diesel and the EGR fires... DEF issues... SCR issues... too much crap to worry about
-Extra 10k up front
-Im old enough to no longer care what people think, no need to be in the diesel club.. just because

My current 5.7 1500 does a great job, would enjoy some extra payload, power, and suspension.. thinking of rear air ride.