Towing with 6.4 hemi

[oldmud14]

I have a 2024 Ram 2500 with the 6.4 hemi and 8 speed trans. I bought it to tow my travel trailer. The RV is roughly 6000lbs. The truck really seems to struggle and I am curious if anyone else has this issue. I thought that this truck would tow that weight with ease but it feels extremely sluggish and very underpowered. If anyone has any input it would be greatly appreciated!

 

[mtofell]

That engine/tranny combo should haul that weight ease but it's tough to really know since we all have different expectations and definitions. Have you towed much before? Same trailer with a different truck? Same truck with other trailers? Towing-wise it should be a good fit but it still is a 6000# sail behind you.

I'd probably start by making sure the trailer brakes aren't dragging. With the truck running, lift one side of the trailer and be sure the wheel spins. You can also check the hubs with a infrared thermometer to be sure they aren't extra hot (as they would be if the brakes were dragging). Have someone apply the trailer brakes a couple times and be sure the wheels free up and will spin again.

 

[max2bob]

i have a 2014 and mine does not struggle at all , plenty of power but it does not like to pass gas stations . i would concur something is either wrong with the trailer or truck .

 

[crash68]

I thought that this truck would tow that weight with ease but it feels extremely sluggish and very underpowered.

You're basically doubling the weight the engine/trans has to pull plus the added wind drag of the trailer. The engine is going to have to wind up further than just driving, it wouldn't be unusual for the RPMs to be pushing the 4K range.
Are you using the Tow/Haul mode?

 

[oldmud14]

Yes

 

[MADDOG]

I am towing just over 6K with my 2024 6.4L and am not having any issues, even up and over the steep grades we have to traverse, so I am wondering about the mileage on your pickup, its service history, if you are using the cruise control, the ERS control and what sort of fuel mileage you are getting.

 

[oldmud14]

The truck has 24,000 miles on it. It has been serviced at the recommended intervals at a ram dealer. This last trip, I had the cruise control set at 65 and the engine was tacking around 4500 on a slight incline. It seemed like the engine was working way to hard for the driving conditions. I am definitely going to investigate the brakes on the camper to make sure they aren’t hanging up. Side note: this last trip was around 70 miles round trip and I used about 3/8 of a tank of gas.

 

[dieselscout80]

I have just over 100,000 miles on my 2020 Ram 2500 with the 6.4L hemi with 4.10 gears and 275/70R18 tires.

It tow my equipment trailer with a NH TC45DA and the trailer and tractor weighs just over 9k pounds and it will gain speed if I ask it to going uphill. I might shift down to fifth or even fourth, but it doesn’t seem to run out of power.

I think really high elevations would change that somewhat but I would still do it.

How is your truck equipped is it stock or modified?

 

[rzr6-4]

The truck has 24,000 miles on it. It has been serviced at the recommended intervals at a ram dealer. This last trip, I had the cruise control set at 65 and the engine was tacking around 4500 on a slight incline. It seemed like the engine was working way to hard for the driving conditions. I am definitely going to investigate the brakes on the camper to make sure they aren’t hanging up. Side note: this last trip was around 70 miles round trip and I used about 3/8 of a tank of gas.

These definitely aren't like the old Chevy small blocks, the hemi's like to rev high to get their power. When I moved across the state a few years ago I was pulling an enclosed trailer down the interstate for most of it, somewhere between 3500 and 4k RPM going about 68 mph. 250 mile round-trip that normally would've taken about 3/4 of a tank took one and a half tanks. And that's with the older 5.7 and the 545RFE, yours should be a little smoother but the principal is the same.

 

[dhay13]

I regularly towed a 9000lb boat with my 2018 with no issues at all. Also towed a 9300lb TT 100 miles once with ease and my son had the same truck as me and towed his 8100lb TT 10,000 miles in 2 years with no issues

 

[HuskerRam]

Your trailer isn't dragging brakes, right?

 

[Zoe Saldana]

I tow a 8K TT and my issue is driving a safe speed on the flats - about 65mph.

Yes, headwinds e.g Texas and hills e.g. Colorado - would challange any motor.

You need to tell us where you tow and at what speed.

 

[crash68]

I had the cruise control set at 65 and the engine was tacking around 4500 on a slight incline.

What tire size and gear ratio does the truck have?

 

[oldmud14]

The truck is all stock with 3:73 gears. I am definitely going to check the brakes on the TT but I am pretty sure they are not dragging. I am towing in eastern Pa.

 

[joesstripclub]

If you are using tow/haul, I noticed my truck is very sensitive to down shift while towing and will hold the gear at higher rpm for longer. If towing on relatively flat terrain I usually run with tow/haul off so it doesn't hunt gears as much for small hills. First tow with my Power Wagon I pulled my toy hauler up to Taylor Park in CO. Fully loaded with water and fuel I was probably pushing 11k lbs. It handled it just fine but cant be in a race to get anywhere. Remember peak torque is rated around 4000 rpm so its going to want to rev to make progress.

 

[HEMIMANN]

Since you have the latest gen HD with the HD ZF, it must be the trailer brakes.

I have the previous gen HD with the 66RFE trans & std 3.73 axle, so have to baby it when towing moderate. Trailer mode shifting (shifts @ higher rpm), locked in 4th gear (1:1, no OD), removed trans cooler thermostat, Red Line C+ ATF trans oil.

So far, so good. 68k miles

 

[SeventyGTX]

Yeah, that is crazy. I am currently looking at possibly a later model 6.4 w/8spd to tow our current 6k trailer. My 1500 5.7/8 spd with 3.92's does fine for power in the Arizona mountains, it's the lighter chassis and air suspension that makes it feel a bit uneasy in wind and around semi's.

 

[2003F350]

The truck has 24,000 miles on it. It has been serviced at the recommended intervals at a ram dealer. This last trip, I had the cruise control set at 65 and the engine was tacking around 4500 on a slight incline. It seemed like the engine was working way to hard for the driving conditions. I am definitely going to investigate the brakes on the camper to make sure they aren’t hanging up. Side note: this last trip was around 70 miles round trip and I used about 3/8 of a tank of gas.

At 65mph and 4500 RPMs, that motor was in its home, jamming away. You were in no danger, and that's just how the Hemi of just about any displacement likes to run - higher RPMs to make more power to move the load.

Back when I had my '17 'Wagon (6.4, 6-speed, 4.10's), I'd pull our travel trailer (roughly the same weight as yours) up north at 65mph with no issues. There's a couple good hills on the way up, one is a couple miles long, and it would downshift about a third of the way up and sing about 4/4500 rpms the whole way up. First time my wife heard it she thought something was wrong, I had to explain to her that it's just where the motor makes power.

You've got to remember that your max torque value is at 4000 RPM, and your max horsepower is at 5600 RPM. This isn't a diesel or an old big block that made big torque values at low RPMs, these are high-revving motors. There is one entrance ramp we used to stop at frequently when headed north, it's about half a mile long and a pretty good grade (7% maybe? I'm honestly not sure), and I tried it while 'babying' the truck with the camper...I was only at 35 mph at the top. I tried again on our next trip while letting that motor sing, and I was at 65 mph and still climbing at the top of the ramp. Sure, my diesels moved bigger loads up that ramp faster, but for a gas motor under load it did just fine.

Let that big V8 sing. Get a better exhaust so you can enjoy the sound of horses running wild.

 

[HEMIMANN]

Gas motors reach peak torque around 4,000 rpm or so, plus and minus depending on gearing. Nature of the beast - lower cylinder pressure at higher rpm than diesels.

Even my former GM Big Block 8.1L behind an Allison 1000 transmission ran up there going up mountain regions.

Diesels have so much emissions crap on them these days they're hardly worth the expense and lowered reliability anymore, all except for full time haulers. And even then, those have reliability problems in the exhaust aftertreatment because it's so complex.

 

[06 Dodge]

Gas motors reach peak torque around 4,000 rpm or so, plus and minus depending on gearing. Nature of the beast - lower cylinder pressure at higher rpm than diesels.

Even my former GM Big Block 8.1L behind an Allison 1000 transmission ran up there going up mountain regions.

Diesels have so much emissions crap on them these days they're hardly worth the expense and lowered reliability anymore, all except for full time haulers. And even then, those have reliability problems in the exhaust aftertreatment because it's so complex.

To me a Hemi screaming at 5,000 rpm reminds me of the old loud smelly Detroit 318 Diesel aka 8V-71, when I first heard one on the hwy I wondered about how soon before parts would fly out of the block, not liking to hear high rpms guess that happens when you been hanging around the Cummins for years