The 6.4 HD Hemi Thread

[regularcab2500]

I work on the road. I have a 45ft fit wheel camper I pull that ways about 17k. Truck pulls it like a dream except for the fact I get anywhere from 6-8mpg. That's why I was curious in doing a swap with a cummins. Someone told me I could do one for about 10k, but decided to come here and ask opinions

You have a 1 ton dually right? You still need a diesel there bro, no question. With any 6.4 youre over weight. Even a dually youre pushing max gcvwr.

 

[tjfdesmo]

Sorry, I am pleased with my 6.4 for my purposes, but as others have already said, if you tow that heavy you bought the wrong motor. Either live with it or trade. A conversion will be huge $$$ and probably an endless can of worms.

 

[River19]

You have a 1 ton dually right? You still need a diesel there bro, no question. With any 6.4 youre over weight. Even a dually youre pushing max gcvwr.

Wow.....I agree with other posters.......to get that trailer within the legal limits of a rig you should be in a Diesel 3500 duelly....even if you got a conversion to Cummins to work bug free......you still can't change the sticker on the door for GCVW.

Better to think about swapping to a Cummins if you plan on toting that 45' beast....

 

[cc rider]

I work on the road. I have a 45ft fit wheel camper I pull that ways about 17k. Truck pulls it like a dream except for the fact I get anywhere from 6-8mpg. That's why I was curious in doing a swap with a cummins. Someone told me I could do one for about 10k, but decided to come here and ask opinions

I find it hard to believe that youre pulling that with a 2500/6.4 and it "pulls like a dream". What kind of axle ratio do you have? Exactly what kind of rv is it? I have a 38' double axle torque toy hauler and mine works (on hills). On flats it does fine. But mine only weighs about 12k, 14k with bikes and loaded up (i havent weighed it yet). I have a 3500 with the 4.10 axle. Im assuming you have a triple axle and are getting crushed in the back from pin weight. My pin is around 2500 so.......
I get anywhere from 8-10 mpg depending on the terrain. I thought about a triple axle, but decided it would not be wise. It was a good choice. We are going to need your vin # and pics

 

[River19]

I find it hard to believe that youre pulling that with a 2500/6.4 and it "pulls like a dream". What kind of axle ratio do you have? Exactly what kind of rv is it? I have a 38' double axle torque toy hauler and mine works (on hills). On flats it does fine. But mine only weighs about 12k, 14k with bikes and loaded up (i havent weighed it yet). I have a 3500 with the 4.10 axle. Im assuming you have a triple axle and are getting crushed in the back from pin weight. My pin is around 2500 so.......
I get anywhere from 8-10 mpg depending on the terrain. I thought about a triple axle, but decided it would not be wise. It was a good choice. We are going to need your vin # and pics

That is what I find interesting about the 6.4L......I tow 5,000-6000lbs up and down hills (horses) and get 9-11.5mpg.......you are towing at least 2-2.5 times the weight I am and are getting about the same fuel economy.

It's like once the 6.4L gets into "work" mode, the ceiling on what it can get done is pretty high.....coming from a diesel, this motor can certainly tow......

 

[drittal]

Wind resistance

 

[Tim Cope]

Just thought I would post a rant about how inept some small town dealers can be. I took my '14 2500 6.4 in for a service and to get the TPMS adjusted.

First even with the instructions copied from here on how to adjust the TPMS I got laughed out of the place. NBD, I am only about 45 mins from a large town in this state (NC) so I figured I would take it down there and get that done. So I told them to change the oil and rotate the tires. I had a coupon for a full synthetic change that I gave them at the desk.

Well when I went to pay I noticed that I thought it was cheaper than I expected and commented on that and the girl said no it was correct. When she handed me the bill I noticed they had put conventional oil in the truck. I said you have made a mistake. you put conventional oil in my truck, I gave you a coupon for full synthetic and I told you up front that it was a 2500 6.4 Hemi. She said no problem, that oil will be fine in it. I said no it won't, there isn't but 2-3 oils approved for it and all of them are synthetic.

She left and came back with the service mgr. and asked what was the issue. I told him and he said I was wrong. I said hold on a minute. I went to my truck and got the owners manual out and he said THAT IS WRONG!

At this point I became livid, and loud. Next thing I knew the general manager was in there wanting to know what was wrong. I told him the main thing was his facility was staffed with a few idiots. The proceeded to tell him that they had put the wrong oil in my truck and his svc. mgr. had the audacity to say the owners manual was incorrect.

Long story short they got everything corrected and offered me a free oil change coupon for the next time but I told them no thanks, I wouldn't be back. I don't believe I want them messing with my truck.

 

[cc rider]

Tim, that's why I do it myself. When I took delivery of my truck, it was dirty. Someone drove it to the dealer to deliver it and was eating in it, changed all the settings in my uconnect, bass was all the way up, their phone was paired etc. I know someone who had a coupon and it worked out to be same price as if you did it yourself. I told him I would still do it myself. It's piece of mind . The less my truck is away from me, the less chance of this happening.

 

[Tim Cope]

Well I usually do and have done it in the past, but. I bought this truck from of all people a friend of mine who is an attorney. It was involved in the recall because of the wrist pins. He bought a new diesel while the engine was being replaced and I bought it from him. He has sued Chrysler several times for clients over the years for warranty issues and he advised me that they were the worlds worst about trying to hedge over warranty issues. He said that if there was ever any question about service issues it was always much, much easier and almost a slam dunk if you had receipts from a dealer proving you had routine service. I figured during the warranty period I would just bite the bullet and get it serviced at a dealer.

 

[Ryan102]

You have to be very careful ... svc managers are 95% of the time complete morons. I always emphasize the fact of putting the correct oil in my truck. Especially since these vehicles now are so damn expensive. IF they give me a hard time I ask them if they know something the engineers who designed the thing doesn't know. Just like the other day, my wife took her scion frs in for an oil change. The book says every 7500 miles. So she's ready for her second oil change at 15000 mi and the svc manager told her she doesn't need one and that it only needs it once a year. Really dude? But I can say with my ram I haven't had any issues with service at all. Even when I had my challenger. I had lots of warranty work done to it and never got questioned about it. I guess it really depends on when and where.

 

[reb0957]

2 things I am really noticing with my truck. Just curious if anyone else notices.

1. Truck doesn't hold MPH well either with or without a trailer using cruise control. Pulling my empty trailer I started using TH for over passes and it was better 1 to 2 mph loss versus 5 without it. For reference I-10 between Lafayette and Houston.

2. Even on level ground for miles I have seen the speed drop 2 to 3 MPH and take a couple of miles to get back up to set speed.

 

[NewBlackDak]

Towed over the Ike last weekend, and experienced the 4K-ish RPM WOT lock thing. The good news is I stayed in 3rd at 55-60 mph the whole time. Admirable for a gasser. 7.7 mpg wasn't so fun.


Sent from my iPhone using Tapatalk

 

[6.4 dude]

I get the same mpg pulling a 16k tank trailer as I do pulling my vac trailer with two ports pots on it. Pots are 48" wide, 80" tall.The pots and trailer way around 5k. They're like dragging a parachute around. It's all about aerodynamics with a gasser.

 

[Wh87gta]

Finally decided to make the jump from my 05 CTD. Picked her up two weeks ago and so far I'm loving it. Couldn't pass up what I thought was a good deal with my trade. Gonna miss the low end torque a bit but drivability and ride is way above my expectations.

 

[Ratket]

ya these Rams have like a 5-7 mph lee way on the cruise control.. in a way it is nice, keeps the truck from shifting but if you're cod kicks in be cause you want it to stay at 75mph.. well then it is going to drive u nuts.. I have found with going down big hills I just lock out 3rd or fourth and leave the cruise on.. that way it doesn't just run away and start down shifting like mad.

 

[Hootbro]

Just a FYI, Amazon has a $10 coupon on the Pennzoil Ultra 0W-40 for a limited time. Makes it $39 a case (6 pack). Cheapest I have seen it.

Amazon.com: Pennzoil 550040856-6PK Ultra Platinum 0W-40 Full Synthetic Motor Oil - 1 Quart (Case of 6): Automotive

 

[Tallsilver]

TPMS Change

Had my TPMS reset to 55 psi. Running 60 psi in front, 50 psi in rear, and lovin' the ride!!

 

[Megazor]

Just finished up a 3500 mile road trip while towing several different trailers.

Since we will be moving soon we decided to take our kick around town car back to the parents house so we have less to move.

95 Tercel (2000lbs) curb weight that was loaded with about 500lbs of other car parts and luggage. Pulled on a U Haul car hauler (2200lbs). I did not scale the trailer but with guessing the trailer weighed in at 4700lbs to 5000lbs. I pulled this configuration from New Mexico to the Black Hills of South Dakota (750-800) miles. The hand calculated mileage was 15.9mpg. I set the cruise at 3 above the posted speed limit (65-80mph) and let the truck do what it wanted. There were a few times I also had to pass slower traffic which I just used WOT (1mpg on the lie O'meter). Over all fuel mileage was better then I expected.

Second Trailer was 24 foot travel trailer. Dry weight was 4000lbs and hauling about 1000lbs of crap... (Generator, 6 cases of water, luggage, etc.) Again I failed at weighing the trailer but guessing it was about 5000lbs.

We towed the trailer to the wife's family reunion in Wisconsin from South Dakota. Stayed a few days and returned to South Dakota. During this trip I was pretty lazy again just setting the cruise at 3 above the speed limit. The only exception to this was on I90 where the speed limit is now 80mph. I set the max speed at 75mph. The most of the trip was at 68mph. With the parachute attached to the truck for 1578 miles the mpg dropped to 8.8 hand calculated. There were a few tanks the average dropped to 5-7mpg.

The return leg from South Dakota to New Mexico was without a trailer. Set the cruise again 3 above the speed limited and fuel mileage was 16.9 hand calculated. Most of the trip was 70-80mph. The truck says the average trip speed was 67mph. My usual cruising on the highway at 55-65 nets anywhere from 18 to 20mpg depending on headwinds and elevation changes.

During the trip while towing the truck never felt under powered even with the 24 foot parachute attached. (I would hope not since it wasn't even at half the tow rating) Maintained the speed limit the whole time and only dropped into 3rd gear on the two long steep hills around Wall, SD. One thing to note, like others here have said, the drag from the trailer is what kills the fuel mileage. I towed two trailers that were almost the same weight with the travel trailer (TT) getting half the fuel mileage. Even when headed down hill the truck had to work against the drag of the TT.

Only negative during the trip was when the outside temperature was above 90 degrees. Parts of NM on the return trip were around 100F. The truck A/C had troubles keeping the megacab rear seat area around 68F. The front of the truck was freezing and the back seats were hot. I had two front vents closed and both rear vents wide open and nothing in the way of airflow.

Nothing like doubling the mileage on the truck during a 12 day road trip.

 

[MN-Ram]

Greetings

First time on here. I read a lot of your guys' posts on this thread when making my decision to buy a 6.4L Hemi vs a 5.7L. Last weekend I picked up a 2015 Ram 3500 Tradesman SRW (with the 6.4).

The mpg's are getting better as I put more miles on it. I logged about 850 miles in the first week. The motor really started to wake up around 600 miles.

I got the 3.73 gears, so I will be a little on the lighter side with regards to towing, but plenty good to haul my 6'x12' enclosed trailer, and firewood come fall. I like the 4,000lb payload.

I opted for the 1-ton, because in MN, tabs for a brand new truck with a GVWC over 10k is only $160/year. The 3/4 ton starts around $550/year and slowly goes down each year. The price was only $1500 more at purchase, but the difference in price will be paid for in tab savings in 4 years - and the 4k payload lasts forever.

In conclusion: so far, I like the thread. I love the truck.

 

[SouthTexan]

95 Tercel (2000lbs) curb weight that was loaded with about 500lbs of other car parts and luggage. Pulled on a U Haul car hauler (2200lbs). I did not scale the trailer but with guessing the trailer weighed in at 4700lbs to 5000lbs. I pulled this configuration from New Mexico to the Black Hills of South Dakota (750-800) miles. The hand calculated mileage was 15.9mpg. I set the cruise at 3 above the posted speed limit (65-80mph) and let the truck do what it wanted.

Wow, you got better mileage towing at 65-80 mph than most here or those on Fuelly.com do unloaded doing only 70 mph.