RAM 2500 6.4 vs Cummins for Travel Trailer with 7500lb GVWR

[DHC4570]

We currently have a Grand Design Imagine 2400BH with a GVWR of 7500lbs (weighed weight loaded for travel for us was 6600lbs) but if we travel more I guess that number will definitely get higher. We have no future plans to get a larger trailer and currently tow this with a large SUV rated to tow almost 9000lbs. We want to travel more and further distances and we feel that for the size of trailer and the amount of travel is where we would prefer to be in 2500 territory. Just wondering if those with experience with the 2500's if the 6.4 Hemi would be up to the task travelling 1000's of miles with some mountain travel as well. My other concern with the Cummins is this travel would be for 1-2 months a year and then otherwise the Truck would only travel a 100-200km a week at best unloaded.

I appreciate any feedback!

Thanks!

I will state up front that I did not read all of the replies...

I drive a 2020 Ram 2500 Laramie, 6.4L Hemi, 4WD, CC, SWB with an Outlaw Premium HD front bumper, Diamondback HD bed cover, 4 PAX, plus a fairly full bed. We tow a GD Imagine XLS 2100BHE with a GVWR of just under 6400lbs. I've never weighed everything but my truck has had ZERO problems towing from southern AZ to Camp Pendleton, CA through the Cleveland National Forest with four 4,000' summits crossed at some seriously steep grades. We've also gone east to vicinity Ruidoso, NM climbing to 7,550' elevation into the Sacramento Mountains of New Mexico with no issues. My father-in-law has a 2019 Ram 2500 Tradesman 6.4L Hemi towing an almost 6800lb GVWR travel trailer. He's close to max weight when he travels as they travel with all of the amenities loaded. Again, no issues. We almost always go together as a family though they do a lot of other traveling without us due to our schedule.

I've been driving turbo diesels since 1993 when I bought a brand new Chevy 2500 with the 6.5L GM turbo diesel (long story why I didn't go Cummins... still smarts...). Blew the head gasket in 2003. In early 2004 found a 95 Dodge 2500 5.9L 12valve Cummins, 5spd, 4wd, SC, LB which I still own. Great work truck, lousy family of four truck... Had and sold an 07 Ram 3500 5.9L Cummins 6spd QC which I traded for the current 2020 Ram as it needed more engine work than I could afford up front (and my wife HATED the seats). While I miss that 07, I haven't regretted getting the 6.4L Hemi, though I did get an extended warranty to 110K miles/8 years. Just in case.

On a side note relating to 1500s... I've NEVER been a fan of towing a travel trailer the size of ours with a 1500. My father-in-law had a Ram 1500 2wd, CC, SB when he first bought his travel trailer. When I recommended he consider getting a 2500 for towing, he said it's well within the towing capacity of the 1500. Nuff said. While that's true, his 1500 was approximately 1,750lbs lighter than the 2500. Our FIRST trip to Camp Pendleton, he was leading. My wife and I were chatting and I never saw the moving truck coming up in the passing lane doing about 20mph faster than we were. It was a gusty, windy day. When that high pressure air mass being pushed by the nose of that truck hit my trailer from behind, it caused me to warble a little bit. Kinda startled me but was really a non-issue. My father-in-law didn't see it coming either as that air mass pushed him onto the shoulder of the road. He over-corrected and almost ran the moving truck off the left side of the road. He didn't say much at the next stop but my mother-in-law was still visibly shaken. I didn't say anything to him. When we departed Cp Pendleton, they headed north for another 4 weeks of traveling. When they got home, my mother-in-law told my wife they are looking for a 2500 and asked us to keep an eye out for one. When my wife asked her what happened, she just said they had a second similar incident...

Now the experienced drivers out there will tell you that they have the skill to handle such an event. While that's great and all, not everyone has that kind of experience. And there are going to be times when you as a driver get complacent. Anyone that says that doesn't happen to them is lying. It happens to all of us. While travel trailers are getting lighter all the time, they STILL have a high aspect ratio that can be affected by cross-wind or the turbulence created by a tractor trailer, etc. I for one prefer to have a tactical (and arguably strategic) advantage thus drive a heavier truck. Just my twin Lincolns. But opinions are like belly buttons, just about everyone has one, and they are all different. (Some just have more lint than others...)

Dave

 

[2003F350]

I will state up front that I did not read all of the replies...

I drive a 2020 Ram 2500 Laramie, 6.4L Hemi, 4WD, CC, SWB with an Outlaw Premium HD front bumper, Diamondback HD bed cover, 4 PAX, plus a fairly full bed. We tow a GD Imagine XLS 2100BHE with a GVWR of just under 6400lbs. I've never weighed everything but my truck has had ZERO problems towing from southern AZ to Camp Pendleton, CA through the Cleveland National Forest with four 4,000' summits crossed at some seriously steep grades. We've also gone east to vicinity Ruidoso, NM climbing to 7,550' elevation into the Sacramento Mountains of New Mexico with no issues. My father-in-law has a 2019 Ram 2500 Tradesman 6.4L Hemi towing an almost 6800lb GVWR travel trailer. He's close to max weight when he travels as they travel with all of the amenities loaded. Again, no issues. We almost always go together as a family though they do a lot of other traveling without us due to our schedule.

I've been driving turbo diesels since 1993 when I bought a brand new Chevy 2500 with the 6.5L GM turbo diesel (long story why I didn't go Cummins... still smarts...). Blew the head gasket in 2003. In early 2004 found a 95 Dodge 2500 5.9L 12valve Cummins, 5spd, 4wd, SC, LB which I still own. Great work truck, lousy family of four truck... Had and sold an 07 Ram 3500 5.9L Cummins 6spd QC which I traded for the current 2020 Ram as it needed more engine work than I could afford up front (and my wife HATED the seats). While I miss that 07, I haven't regretted getting the 6.4L Hemi, though I did get an extended warranty to 110K miles/8 years. Just in case.

On a side note relating to 1500s... I've NEVER been a fan of towing a travel trailer the size of ours with a 1500. My father-in-law had a Ram 1500 2wd, CC, SB when he first bought his travel trailer. When I recommended he consider getting a 2500 for towing, he said it's well within the towing capacity of the 1500. Nuff said. While that's true, his 1500 was approximately 1,750lbs lighter than the 2500. Our FIRST trip to Camp Pendleton, he was leading. My wife and I were chatting and I never saw the moving truck coming up in the passing lane doing about 20mph faster than we were. It was a gusty, windy day. When that high pressure air mass being pushed by the nose of that truck hit my trailer from behind, it caused me to warble a little bit. Kinda startled me but was really a non-issue. My father-in-law didn't see it coming either as that air mass pushed him onto the shoulder of the road. He over-corrected and almost ran the moving truck off the left side of the road. He didn't say much at the next stop but my mother-in-law was still visibly shaken. I didn't say anything to him. When we departed Cp Pendleton, they headed north for another 4 weeks of traveling. When they got home, my mother-in-law told my wife they are looking for a 2500 and asked us to keep an eye out for one. When my wife asked her what happened, she just said they had a second similar incident...

Now the experienced drivers out there will tell you that they have the skill to handle such an event. While that's great and all, not everyone has that kind of experience. And there are going to be times when you as a driver get complacent. Anyone that says that doesn't happen to them is lying. It happens to all of us. While travel trailers are getting lighter all the time, they STILL have a high aspect ratio that can be affected by cross-wind or the turbulence created by a tractor trailer, etc. I for one prefer to have a tactical (and arguably strategic) advantage thus drive a heavier truck. Just my twin Lincolns. But opinions are like belly buttons, just about everyone has one, and they are all different. (Some just have more lint than others...)

Dave

There are a LOT of good points here. Don't get me wrong, 1500s are very capable trucks, but once you get into RVs it's a different ballgame from a boat or a utility/flatbed/equipment trailer. It may not be heavy, but it has HUGE surface areas on all sides, and are susceptible to any kind of turbulence. In that case, the longer/heavier your tow vehicle, the better you can fight sway. 1500s just aren't that heavy compared to a 2500/3500, so they're at a massive disadvantage.

And you're absolutely right - all it takes is someone getting complacent while they're pulling their rig for disaster to strike. I do my best not to, and I'm constantly checking mirrors and looking down the road for what's coming at me, but there have been times I've been surprised. Thankfully nothing serious, but a few times I've had someone pull out in front of me or cut me off while towing, and I'm sure they've heard me cursing over my horn.

 

[Ratman6161]

... The 6.4 Hemi wants 89 octane. That will get you up close to diesel prices for fuel...

Why? Yours eems to be a 2016 from your signature? Mine is a '22 and the owners manual specifies 87. I've tried all the various fuels available in my area that my truck can run on: 88 E15, 87 E10, 89 E10, 91 E10, 93 E10 (note: ethanol free is not legal in MN for road vehicals less than 20 years old). I've also towed with all of those except the 93. Did not make a bit of difference.

 

[2003F350]

Why? Yours eems to be a 2016 from your signature? Mine is a '22 and the owners manual specifies 87. I've tried all the various fuels available in my area that my truck can run on: 88 E15, 87 E10, 89 E10, 91 E10, 93 E10 (note: ethanol free is not legal in MN for road vehicals less than 20 years old). I've also towed with all of those except the 93. Did not make a bit of difference.

When I had my '17 6.4, the owners manual said 89 was recommended, but that it was perfectly safe to run 87. The problem is in my area, not all stations have 89/90, and those that do don't sell much of it, so it was either premium (91+) or regular 87. I ran it on premium for a long time, but switching to 87 I didn't really notice any power falloff. For most people in the country it will probably be the same.

At higher altitudes, though, I could see the difference being noticable due to the lack of oxygen causing spark knock.

 

[Riccochet]

My 2020 manual specifies 89, but you can run 87 at the risk of reduced performance. How much reduced, that's anyone's guess. The engine is going to retard timing before you even realize knock is happening. Might be only a degree or two to compensate, which in "seat of the pants" feel won't amount to much. Now if you got some really bad 87 that might be enough to notice.

I always run 89 since I'm always towing something, and want all the beans available.

 

[nlambert182]

If it's "reduced performance" like our Armada Platinum.. it drops the HP from 400 down to 390 (according to Nissan). TBH.. in that thing, you can't tell any difference at all. They recommend 93 but say that 87 is fine. We run 93 but if we are only near a station with 87 I don't pass it up.

 

[HEMIMANN]

On another thread, can't recall which, was a big discussion on Hemi engines and gasoline octanes.

One member had diagnostics and recorded ignition timing vs. octane. The 87 octane gas pulled the ignition timing AND caused knocking to do so. ECM goes into short term cycling of ignition timing, advancing/knocking/re-tarding. Don't recall how many times before it sets long term ignition re-****. So you do lose a little power and mlieage.

MORE important is HOW the ECM accomplishes it - finding a lower octane gas by letting the engine knock repeatedly ain't good in many of our opinions.

Use the 89 octane.

 

[2003F350]

On another thread, can't recall which, was a big discussion on Hemi engines and gasoline octanes.

One member had diagnostics and recorded ignition timing vs. octane. The 87 octane gas pulled the ignition timing AND caused knocking to do so. ECM goes into short term cycling of ignition timing, advancing/knocking/re-tarding. Don't recall how many times before it sets long term ignition re-****. So you do lose a little power and mlieage.

MORE important is HOW the ECM accomplishes it - finding a lower octane gas by letting the engine knock repeatedly ain't good in many of our opinions.

Use the 89 octane.

As a powertrain engineer, the amount of knock that the ECM allows to happen before it pulls timing is so minuscule you wouldn't notice it. It's not like spark knock that most hot rodders and engine builders are used to, heck if you were outside the truck when it happened you probably wouldn't even hear it unless you were actively listening for it with a mechanic's stethoscope - at lower elevations, anyway. I'm sure it's more pronounced at higher elevations. Same with the power falloff - likely much more pronounced at higher altitudes.

Is any spark knock a good thing? Not really, no. Is the amount that the ECM allows acceptable? Absolutely. How do I know? Because I used to tune a LOT of different engines in the past, and EVERY stock one had at least a small amount of knock, regardless of what fuel was run in it. The ECM has a default table it runs off of to advance/retard timing, and the only way to eliminate all knock is to adjust that table to fit the individual vehicle.

 

[HEMIMANN]

As a powertrain engineer, the amount of knock that the ECM allows to happen before it pulls timing is so minuscule you wouldn't notice it. It's not like spark knock that most hot rodders and engine builders are used to, heck if you were outside the truck when it happened you probably wouldn't even hear it unless you were actively listening for it with a mechanic's stethoscope - at lower elevations, anyway. I'm sure it's more pronounced at higher elevations. Same with the power falloff - likely much more pronounced at higher altitudes.

Is any spark knock a good thing? Not really, no. Is the amount that the ECM allows acceptable? Absolutely. How do I know? Because I used to tune a LOT of different engines in the past, and EVERY stock one had at least a small amount of knock, regardless of what fuel was run in it. The ECM has a default table it runs off of to advance/retard timing, and the only way to eliminate all knock is to adjust that table to fit the individual vehicle.

That's not what a member documented via tool scan.

 

[ramffml]

That's not what a member documented via tool scan.

Wasn't it @Hemi395 who ran this test?

 

[HEMIMANN]

Wasn't it @Hemi395 who ran this test?

I can't remember short term details anymore - I just remember a whole series of datalogger printouts and being convinced using 87 octane as standard fuel was not good for the engine the way the ECM ignition timing control was set up.

All the data was there showing how repetitively knocked until it went into long term re*tarded ignition timing.

For me, that said 87 octane should only be used in a pinch - not routinely. Even the wording in the manual alludes to this - 89 octane is preferred. Ask yourself "why?"

 

[68PowerWagon]

I bet the OP wishes he didn't open this can of worms. Seems we digressed a bit here.

 

[HEMIMANN]

I bet the OP wishes he didn't open this can of worms. Seems we digressed a bit here.

Nah - even though Forums aren't the entire public, they're still large enough to have a wide variety of people. Not quite as bad as public speaking, but work was a helluva lot easier at a company with a great technical culture. Until it got bought out be a mega corporation, that is.

What I thought was normal life was actually an exception. Even this place is far better than most other Forums in my experience. You think this is bad? Try BITOG

 

[zenderxt]

We ultimately decided to do a build, and went with a Bighorn 2500, 6.4 Hemi, 4.10 Gears. While the Diesel had a lot of allure to me, the 10k price tag, and the concern over the emissions issues driving minimally most of the year except maybe 2 months where it would get worked hard was a large concern. Since we have no future plans of getting a larger trailer, 7500lbs (if we maxed the trailer) is likely not hard work for the 6.4. Appreciate everyone's feedback on this thread.

 

[ramffml]

We ultimately decided to do a build, and went with a Bighorn 2500, 6.4 Hemi, 4.10 Gears. While the Diesel had a lot of allure to me, the 10k price tag, and the concern over the emissions issues driving minimally most of the year except maybe 2 months where it would get worked hard was a large concern. Since we have no future plans of getting a larger trailer, 7500lbs (if we maxed the trailer) is likely not hard work for the 6.4. Appreciate everyone's feedback on this thread.

I'm sure you'll be happy with your truck, I definitely would!

Also, it's very nice to hear the actual outcome of a 12 page discussion, thanks for reporting back.

 

[chopperdog45]

I'm sure you'll be happy with your truck, I definitely would!

Also, it's very nice to hear the actual outcome of a 12 page discussion, thanks for reporting back.

Yeah, it seems to be pretty rare to actually hear about the outcome.