6.4 or 6.7 for the next truck?

[Night RAM]

Father just got a mid sized fifth wheel travel trailer that weighs 12000 max. He is looking at getting a truck in the future to tow it as it will just be sitting at a campground for now.


That being said, he is really looking at the 6.4 as the gas motors are getting more powerful and can tow a decent amount of weight. He wants to take the trailer down to Florida every winter when he retires in a few years and won’t use the truck in the winter at all.


Should he look at the 6.4 Hemi or do y’all think he should go with the 6.7 Cummins on his next truck with towing the trailer in mind.

 

[Deki]

Depending on the king pin weight of the 5th wheel, he can definitely go with a 2500 with the 6.4 and 4.10s or he can get a 3500 srw with the 6.7. The payload is what I would look at, as a 12000 pound trailer will have between 2000 to 2400 of hitch weight and that will max a 6.7 2500 out with its 2200 pounds of paylpad, but won't even hit half opayload, 6.7. The gas 6.4 2500 also has 3000 to 3300 pounds of payload. I don't think a 12k pound trailer will be too much for the 6.4 and if he's not towing a lot, then I would go with that and save himself 6 to 10k.

 

[Night RAM]

He said the king pin weight is about 1800 pounds and 150 pounds for the fifth wheel plate.

He also said he is looking more at the 3500s

 

[mtofell]

I have a 6.4 Hemi 2500 with 3.73 gears and a 5th that sounds nearly identical. 9000# dry, max of 12,000#. The truck gets by and does okay. The tranny is not great and has some crappy gear spacing. Of course, a diesel would be better but it's not like I'm a hazard on the road or hold up traffic.

I'm right at my 10,000# GVWR with a 250# slider hitch and family in the truck. I'm nearly 1000# under rear axle weight and close to the same under the front. If I were starting again from scratch I'd probably go diesel but your Dad is correct that these newer gas truck are much more capable than ones just a few years ago. Gas and 4.10 gears would certainly be better than my 3.73s but I don't think the difference is as much as some might expect. I've considered doing a re-gear to 4.56 or something close but, again, it's not like I'm totally struggling.

By far my biggest complaint about the Ram gassers is the tranny. The gear ratios are borrowed from the diesel and the 1-2 gap is a mile when towing. The tranny also has some annoying shifting habits that really show when towing but that can be eliminated by just shifting manually.

It's always a tough question these days because the trucks have gotten so nice and capable. My setup is world's better than anything 15 years ago but there's always something better out there

 

[Docpaulo]

Go gas as diesel doesnt like sitting idle for months... cheaper to maintain... if he was towing monthly get diesel...

Power is not a limiting factor at those weights... payload is a bigger concern

 

[MADDOG]

I've done a similar sized 5'vr with a 6.4L HEMI and my current CTD. I much prefer the CTD over the 6.4L powered unit. More torque to move the load from a dead stop, the compression brake working in concert with the Tow Haul mode is fantastic and the CTD gets a LOT better mileage.

I live out in the West and no matter what direction I go I end up pulling some pretty decent grades. The 6.4L HEMI is a fine engine but with that much weight, it just struggled wayyy too much. The CTD doesn't seem to even care...it just chugs along without any drama.

I don't tow it all the time, usually 4 or 5 times a year on average, but every time I pull it with the CTD I feel a lot more comfortable in that I feel I have the power and functions necessary for a safe tow. Now that I am retired I will be towing more and I am very glad I have the Cummins.

 

[tdeperte]

The cummins is a no brainer for that weight and distance. The fuel mileage will be better. The engine braking and exhaust brake will be superb. There won't be a screaming gasser when climbing a grade. It will be a much more enjoyable driving experience.

 

[Docpaulo]

The cummins is a no brainer for that weight and distance. The fuel mileage will be better. The engine braking and exhaust brake will be superb. There won't be a screaming gasser when climbing a grade. It will be a much more enjoyable driving experience.

No doubt it is better... but the 6.4 will still get you there and cost less per year even after gas... including the cheaper monthly payment...

The diesel is great if you use it a lot... low mileage old diesel engines can have issues

So its not really a no brainer... it depends on one's needs and budget

 

[SouthTexan]

I tow a 14k 5ver with my 2500. I am not really concerned with the GVWR or payload because I know it is limited by EPA/USDOT regulations and not actual carrying ability.

The diesel sitting for too long is a bit of a myth as well as many others that have been stated. Don't take my word for it... Total Cost of Ownership: A Diesel Versus Gasoline Comparison

It basically boils down to how much power your are willing to pay for initially as with an engine upgrade option. You will get most of that back on resale, but it still may not be worth it for some.

 

[BossHogg]

What SouthTexan said. There is a ton of misinformation floating around about modern diesels, almost all of it incorrect and typically propagated by folks that don't have one.

There are a few dollars of difference in maintenance costs between my two RAMs but the amount isn't worth the discussion.

I would go diesel for what you are pulling and the distance you are pulling.

 

[reek]

The diesel sitting for too long is a bit of a myth as well as many others that have been stated. Don't take my word for it... Total Cost of Ownership: A Diesel Versus Gasoline Comparison

http://umtri.umich.edu/sites/defaul...Cost_. of.Ownership.Paper_.2015.Final2__0.pdf


the more I read, info like this has pretty much reduced the "fear" of owning a newer diesel for me. My next truck will likely be a Cummins. I'm even starting to warm up to the idea of NOT getting the manual trans.

of course, my timing for a new truck should coincide with the next gen of HDs coming out. by chance, if they throw the 8 speed trans in with the 6.4, I'm back to hemming and hawing.

 

[mtofell]

if they throw the 8 speed trans in with the 6.4, I'm back to hemming and hawing.

Hell, I'd settle for a 6spd with reasonable ratios that are designed for the engine. But, yeah, an 8spd would be nice . I'd have to think being the first manufacturer to put more than 6 speeds in an HD truck would create some "buzz" and sell some trucks.

I'm largely in the same boat, though. Would love to get a new truck and could afford it. But, my current Hemi is still a super nice ride, tows my trailer adequately, and is nearly paid for. I also have the Lifetime warranty that I hate to throw away.

 

[DodgeDude99]

Diesel all the way. ‘14 2500 CC 4x4
Empty I can get 22-24 highway doing 60-65. I pulled my ‘63 Impala on a hauler for 75 miles on flat Illinois highway & got 18.
Moved my stepson back from Vegas, 3 adults, can full of crap, bed in the bed, clothes, tools, pots & pans, pulling his S10 that has the cab full of clothes, tv, & other electronics, & that bed full of tools, bike, grill, lawn furniture.
13-15 mpg doing 70 mph from Vegas to Chicago.

I drive about 14k miles a year, fuel filters & air filter once a year from Amazon for $115, oil changes are twice a year at $50-$60 depending who has the oil on sale.

Resale is also better, look at 15 yr old diesels & 15 yr old gassers, that ‘02 still goes for high teens low 20’s

 

[sidpost]

There is a lot of misinformation and general bad thoughts by people who have never owned a diesel HD pickup or small truck. If you haul big weight, a diesel has huge advantages on the road. If you have a lot of time 'in service' even without going down the road diesels have a big advantage. I say this as someone who grew up on a farm with everything from 1-ton diesel pickups to semi-trucks.

Routine maintenance is a 'wash' in most cases due to longer service intervals and reduced routine needs in general for a diesel (DPF tweaks this a little though). However, if you need to work on a diesel, the bills are almost always much higher than similar gas engine repairs. Replacing a starter or alternator in a diesel in some cases can almost buy a short block gas engine depending on circumstances. It is a lot easier to flush out a gas fuel injection system versus pressure testing, cleaning or, repairing fuel injectors or fuel pumps on a diesel.

In terms of fuel cost, it really depends on how many miles per year and whether those miles are loaded or not. Empty, most modern gas engines will rival modern diesels in heavy pickups running lightly loaded, though higher diesel costs now affect the math a bit. While gassers will pull heavy loads, fuel consumption goes way up. In terms of diesels, some are more efficient than others but, in general Dodge Cummins are at the top in MPG.

Now overall costs, adding the diesel option is a huge upfront cost. Whether this makes sense financially depends on the miles driven each year and how heavily those miles are 'loaded'. We had gasoline powered wheat trucks that made sense because they were basically only used 3 weeks a year. They went to the wheat elevator the same as the diesels but 2 to 4MPG was the norm along with road speeds of 20 to 35MH versus the diesel that would leave them standing still with a much heavier payload (torque rules here).

In terms of ease of travel and comfort, a diesel makes pulling a heavy trailer in retirement a whole lot easier, more comfortable and, enjoyable. A gasser is certainly capable too so, ultimately either option will get you to your destination. It all depends on how you want to get there and how often you intend to go as to whether a diesel or gas option make more FINANCIAL sense.

 

[Ram13BH]

Diesel all the way. ‘14 2500 CC 4x4
Empty I can get 22-24 highway doing 60-65. I pulled my ‘63 Impala on a hauler for 75 miles on flat Illinois highway & got 18.

I am 100% on the side of diesels for any towing/hauling situation, BUT...I REALLY WANT TO KNOW how you get that kind of mileage out of a 6.7L 4x4 when I [and everyone I know] can't get close to that. I get 15-15.5 around town and 18-19 empty highway.

 

[SouthTexan]

I agree, 22-24 mpg his kind of hard to believe even in my deleted truck. The lie-o-meter may say 22 mpg highway, but I am consistently 17-17.5 mpg hand calculated at the end of the tank. I might get 1 or 2 mpgs better if I drove 60 mph instead of 75 mph down the highway, but I don't think 22.24 mph is possible.

Although, it is nice to see a 6.7L owner not afraid to call another out if they think something is off of over exaggerated Some of the others will not if it is a positive remark about their engine no matter how ludicrous the story gets.

 

[Ratket]

Low 20”s hwy driving can be had in a cumin’s all day long. Just depends on the driver, set up of the truck. Also the lower 3:42 gear helps.

Texan ur *** is lifted or lvled on 35”s.. if u where on 33”s at stock height u would get better lol

 

[SouthTexan]

Is that lie-o-meter or actual hand calculated?

Deleted my best tank with 99.9% highway driving 70 mph was 19.2 mpg hand calculated while the lie-o-meter said 20.7 mpg. Non-deleted my average was around 14.5 mpg hand calculated and the best tank I ever got driving 99.9% highway back then was was 17.3 mpg hand calculated. I have no doubts that the lie-o-meter will say 22-24 mpg for a brief instant going down highway, but the hand calculated may be another story.

I have also learned that these trucks vary wildly when it comes to how accurate the lie-o-meter is. Some trucks are within .5 mpg all the time while others are more than 2 mpg off. Heck, even my tunes have different accuracy. When I have my Hardway tune loaded then it is about 1-1.5 mpg off while the Anarchy tune is no more than .5 mpg off when I have it loaded. Regardless of which one is loaded and how much the lie-o-meter is lying, I still get the same hand calculated numbers at the end of the tank with both.

 

[Ratket]

The trick is slowing down, only way I have seen high mileage achieves is 65Mph or slower. I got caught in a 55 mph on flat hwy and mds active the whole time, I know with out a doubt I was netting massive mpg”s but as soon as we got out of the 15 mile construction zone I was running 83mph with no mds and was just drinking the gasoline like a sorority group at a frat party lol

 

[SouthTexan]

The trick is slowing down, only way I have seen high mileage achieves is 65Mph or slower. I got caught in a 55 mph on flat hwy and mds active the whole time, I know with out a doubt I was netting massive mpg”s but as soon as we got out of the 15 mile construction zone I was running 83mph with no mds and was just drinking the gasoline like a sorority group at a frat party lol

True, but speed and load has a much greater effect in gasoline than it does with a diesel engine. Hence the reason why diesels are more efficient tow engines. Don't get me wrong, the mileage will decrease with a diesel as speed increases, just not nearly as much as it would with a gas engine. Especially not as much as going from 17.3 mpg like I did at 70 mph when I was stock to 22-24 mpg like he said he did at 60 mph with his stock truck. At most you may see a 1.5 mpg difference (if that) by the end of the tank with a diesel.