Towing report 6.4 Hemi...good, bad, underwhelmed

[RoadDog66]

Well today was the first real test of my 6.4 towing our 7000 lb loaded travel trailer with 500 lbs in the bed about 140 miles in the MD hills & shorter mountain grades in PA. I gotta say I was underwhelmed. I don't know if it's the poor 6-speed gearing choices in the 66RFE or the torque management or both, but my 317hp/385lb ft torque Titan with 3.36 gears felt like it had more grunt making the same trip as it did with the 6.4 and 3.73 gears.

The Ram's stability & ride was 10x better than the Titan, but I sure expected more from the Hemi on the hills. I passed a few semis on the steep grades, but the 6.4 worked for it. I locked out 6th and used tow/haul mode for the trip, but 4th was the Ram's favorite gear and it spent a good amount in 3rd and occasionally 2nd on the hills. And from a stop, the shift from 1st to 2nd on a grade was terrible. There's absolutely no power under 2500 rpm and that's where it drops into 2nd with major lag. Unloaded and not towing this truck has enormous power and the shifting rpm drop off is much less pronounced.

Will the 6.4 Hemi tow, yes. It's just not how I was expecting it to be. Saw 8.3 mpg...nearly same as my Titan (7.2 - 8.6 mpg depending on load). Granted the Ram weighs nearly 1500 lbs more and has twice the payload so similar mpg's were expected. I did only have 1275 miles on my odometer starting out today, so maybe it'll get better after another 3-4 thousand miles and an oil change (I'm really really hoping). I want to love this truck for towing as much as I do for non-towing use...but teetering on the fence.

 

[Ratket]

Get some more miles and the mpg may get better, depends on you're driving style though. If u are up for it look at some performance parts, mainly a tuner. Oh and if u really want a difference, find a good shop and swap to 4:56 gears- then you will really be happy.. or trade it for a diesel lol..

 

[oz97tj]

I haven't towed with mine but just driving around I feel the same way. I had a '14 half ton with the 5.7 and 8 speed tranny. That tranny is soooooooo much better than this 6 speed. It made it feel like it had way more power than this truck.

 

[Bigdaddy]

Yeah, you might want to go with the diesel but other than that I'm happy with my 5.7 Hemi 2500 but I don't have a trailer yet.

 

[River19]

I just did yet another 400 miles round trip tow of our 6000lb horse trailer with about 500-600lbs of gear in the bed out to NY through the Berkshires and our 6.4L tows like a dream. No issues on the hills with power. Yes, Tow/Haul loves 4th......3rd will pull all day long uphill and accelerate our load well past legal speed limits. It will rocket from 62mph right up to 66mph+ before I know it up some of the larger grades.

If I'm at 50-55mph behind a big rig uphill it will downshift straight from 4th to 2nd which can be harsh but that is controllable.

We were paired with a friend of ours towing 2 more horses with a newer F350 with the 6.2L and she was to the floor tached out at 5,000+ rpm heading out of rest areas and entrance ramps and I just run away from her without even coming close to pushing the 6.4L. That surprised me when she said she was floored each time.

We got the same mpg we always get when towing the horses 10.5mpg give or take.

 

[RoadDog66]

River19 are you 3.73 or 4.10's?

If I can get to where I'm getting 10's towing I'll be very happy. The 4th to 2nd jump in T/H mode is annoying when sometimes I know 3rd is plenty. Maybe the computer is still learning and will smooth out the shift points.

Ratket, I'm not ready or able to handle a gear swap yet. Really shouldn't need one or even have to consider it with 410 hp/429 lbft torque. Like I said that's nearly 100 hp more than my Titan had, but hooked up it felt like 100 hp less. Maybe after 50K miles I'll consider it, but we'll see. I just didn't think the hills/grades we climb here are that severe. Maybe they are steeper than I thought. I might look into exhaust upgrades and pray a tuner company can find a way to rework the torque mgmt. Heck if Dodge/Ram could just flash the tranny with new shift points that might help.

Oz96 & Bigg Daddy, the truck is fantastic unhooked. Great power and smooth. Just pulling a load it seems to be off because of the 66RFE shift points. It tows it fine, i was just expecting more I guess.

The Mrs didn't seem to notice any issues so that's half the battle. The engine sounds great in 3rd under load, but dropping to 2nd slit gets a little whiny. Was hoping to get farther out of each tank of fuel especially with 31 gallons, but distance to empty sure seems to drop quickly. I'll post more after the return trip.

 

[preachp]

Hi Op,
These trucks "learn" how we drive them and adjust themselves to it. You may need to put some more miles for it to settle in. Also for some reason, at least on the 65RFE there are some funky shift habits but all in all my 1500 is a great truck and pulls like a champ even with the 3:55 gears. Gas mileage, well it's a truck not an econo box, so while they 30-40 mpg, I can pull them around all day long. I don't know your truck so I am just making general suggestions. But based on my experience with the 5.7 and 65RFE you should have no issues pulling a 7000 LB trailer around.
Good luck with the truck,

preachp

 

[River19]

River19 are you 3.73 or 4.10's?

If I can get to where I'm getting 10's towing I'll be very happy. The 4th to 2nd jump in T/H mode is annoying when sometimes I know 3rd is plenty. Maybe the computer is still learning and will smooth out the shift points.

Ratket, I'm not ready or able to handle a gear swap yet. Really shouldn't need one or even have to consider it with 410 hp/429 lbft torque. Like I said that's nearly 100 hp more than my Titan had, but hooked up it felt like 100 hp less. Maybe after 50K miles I'll consider it, but we'll see. I just didn't think the hills/grades we climb here are that severe. Maybe they are steeper than I thought. I might look into exhaust upgrades and pray a tuner company can find a way to rework the torque mgmt. Heck if Dodge/Ram could just flash the tranny with new shift points that might help.

Oz96 & Bigg Daddy, the truck is fantastic unhooked. Great power and smooth. Just pulling a load it seems to be off because of the 66RFE shift points. It tows it fine, i was just expecting more I guess.

The Mrs didn't seem to notice any issues so that's half the battle. The engine sounds great in 3rd under load, but dropping to 2nd slit gets a little whiny. Was hoping to get farther out of each tank of fuel especially with 31 gallons, but distance to empty sure seems to drop quickly. I'll post more after the return trip.

I'm on 3.73s with the larger tires in my profile.

I've driven the MD hills going towards WV/KY and those are some steep long grades for sure, no doubt about it. I have never towed through there though. That being said I tow on plenty of steep rollers of 1+ mile in length plus some multi mile grades big rigs drop to 45-55mph on and have had good luck.

You can also drop out of Tow Haul and manually drop from 4-3 I believe, I have never done it, but I had 3 harsh 4-2 shifts yesterday that bugged me. But overall I don't miss my diesel much when I tow. Granted it was a warmed over 7.3L and not a new Cummins, but still, the torque curve on this 6.4L is very nice and flat once you get into the 2500+ rpm range. Gassers need to rev a bit and I'm also getting used to that

 

[Ratket]

hemi fever and jay greene both have custom tunes for the 2500 with 6.4.

 

[River19]

hemi fever and jay greene both have custom tunes for the 2500 with 6.4.

Does it adjust the shift points in tow/haul mode or just give you a minor bump in power?

 

[tjfdesmo]

RD66, I pretty much agree with your summary. I like my 6.4, and it suits 98% of what I do, but it does feel doggy for the ratings it comes with. I chalk it up to all the nanny electronics. When engines were mechanical you could wring them out for 100% of what they had, but with this new stuff every input you make is second guessed by the "magic box". I am convinced the 6.4 is "over managed".

 

[River19]

Odd, I wonder if they did something with the 2015s as I said, my 2014 has plenty of juice. The shifting is a little wonky (ie. 1st to 2nd falls off a cliff unless you hammer it) but on the road power is great.

I came from a modded 7.3L diesel with about 350hp at the wheels and it towed fantastic. The diesel certainly liked hills more than the gassers but if you keep the revs where they need to be on the 6.4L it has more than enough engine to move things well.

I've also had 1800lbs of payload in the bed up and down mountains to northern New England pushing 70-72mph the whole way without even breaking a sweat.

Heck I have even been towing with the A/C rocking as well......

Are you towing at sea-level?

 

[RoadDog66]

Odd, I wonder if they did something with the 2015s as I said, my 2014 has plenty of juice. The shifting is a little wonky (ie. 1st to 2nd falls off a cliff unless you hammer it) but on the road power is great.

I came from a modded 7.3L diesel with about 350hp at the wheels and it towed fantastic. The diesel certainly liked hills more than the gassers but if you keep the revs where they need to be on the 6.4L it has more than enough engine to move things well.

I've also had 1800lbs of payload in the bed up and down mountains to northern New England pushing 70-72mph the whole way without even breaking a sweat.

Heck I have even been towing with the A/C rocking as well......

Are you towing at sea-level?

That's good to hear. I think i just had too high of expectations. Didn't think I'd see 2nd going up a hill unless it was from a starting run. There's no lack of ability in the 6.4 Hemi just was thinking Batman & instead got Robin/Nightwing

Hopefully it'll learn my driving style soon and keep me smiling

 

[RoadDog66]

Cuz no matter what we aren't missing out on this view

 

[theviking]

I doubt there is any significant difference in the programming but the tuner's aren't out yet for the 2015 6.4. Will be very interested to see how much a custom tune wakes the motor up. IMO, the poor tranny gears along with 3.73's instead of 4.10's are the big issue here. Would love to hear feedback on 4.56's if anybody ever gets around to installing a set.

 

[Tim Cope]

I have been pulling a 24' boat (around 6.5K) I have found just do away with the tow/haul and go the manual route and you will be much more happy on the steep hills and long grades.

 

[avolnek]

11,000 pounds and 36' long... Trucks seems to do okay... I wouldn't say that I am dissatisfied with it but i'm also not going to brag about it. After all it is a gas engine.

After towing with a 5.9 cummins a gasser is just a gasser. Had i not towed with one i may compliment it...

in all honesty though the 6.4 does pretty dang well for what it is... On the hills i typically lock her into 4th and let it run... rarely shifts... on the flats it will get into 5th but 4th seems to be the sweet spot...

as mentioned before though, the truck itself handles the load so incredibly well... leaps and bounds above anything else i've owned... only thing better would be a dually... the truck is pretty much maxed out on payload and towing cap but yet doesn't sag past level and pulls just fine...

 

[oz97tj]

I doubt there is any significant difference in the programming but the tuner's aren't out yet for the 2015 6.4. Will be very interested to see how much a custom tune wakes the motor up. IMO, the poor tranny gears along with 3.73's instead of 4.10's are the big issue here. Would love to hear feedback on 4.56's if anybody ever gets around to installing a set.

Mine is a Power Wagon with 4.10s but it does have 35s. As said by others, this truck is held back by the tranny.

 

[RoadDog66]

11,000 pounds and 36' long... Trucks seems to do okay... I wouldn't say that I am dissatisfied with it but i'm also not going to brag about it. After all it is a gas engine.

After towing with a 5.9 cummins a gasser is just a gasser. Had i not towed with one i may compliment it...

in all honesty though the 6.4 does pretty dang well for what it is... On the hills i typically lock her into 4th and let it run... rarely shifts... on the flats it will get into 5th but 4th seems to be the sweet spot...

as mentioned before though, the truck itself handles the load so incredibly well... leaps and bounds above anything else i've owned... only thing better would be a dually... the truck is pretty much maxed out on payload and towing cap but yet doesn't sag past level and pulls just fine...

Yeah that thing is a beast. Love it! The 2500 is a quantum leap beyond the 1500s for weight mgmt & road feel while hauling/towing. Seeing what you and others are towing with theirs I'm confident things will improve with mileage & shifting after a few thousand miles and some more trips towing.

I'm gonna try some manual shifts on the return trip. My gear selector wasn't very intuitive on the screen but it did seem to do what I wanted even if the gear choice on the screen didn't change.

 

[drittal]

I'm testing out my 6.4 this weekend. Talked the boss into a 3 day weekend, so us and another couple are loading up the toy hauler and heading to Sturgis.