5.7 Hemi VS 6.4 Hemi

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katactical

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15' 2500 6.4 HEMI
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6.4 HEMI
Been looking around here for awhile just haven't posted anything .
I an looking at a new 14 2500. I know it has been beat to death but looking for real numbers and help on choice of the 5.7 or 6.4
What are the real world numbers (MPG) for the 2500 CC 5.7 with 3;73 gears . This truck will just be a driver and pull light goose neck when I need to .
6.4 guys can chime in also with 6.4 MPG but haven't seen many posts on the 5.7 MPG.

Thanks in advance !!!!!!!!!!!
 

HemiRoar

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Toronto
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2010
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5.7L Hemi V8
i dont own a 2500 but essentially what i have read is that the 5.7 is powerful enough however the mpg arent the best as the frame is hefty.

the 6.4 is more powerful and moves that frame with ease, daily driver or towing. not comparable to the ctd but a lot better than the 5.7, and the mpgs are similar, if not slightly better.
 
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katactical

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15' 2500 6.4 HEMI
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6.4 HEMI
I have been hearing the 6.4 gets as good if not better than the 5.7 . Im not buying the truck for mileage but every little bit help . Thanks
 

mtofell

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Hemi 6.4
I've never owned a 5.7 Hemi but I can tell you the 6.4 is awesome.....

Every time I tow with it I'm more and more impressed. I took it out last weekend over the nearby mountain pass which is roughly 4500 ft and I was able to easily maintain hwy speed up some steep grades while towing my TT. I was loaded to the hilt with water, kids, firewood and, of course, beer :) Trailer axles were 7100# total, drive axle 5000# and steer axle 4100#. So, 16,000# and change and it was a beast. I'm coming from a nice diesel (Duramax) and am hard pressed to tell much of a difference. Even at elevation where gassers lose some power.

Mileage wise I'm at about 14 with roughly 50/50 city hwy driving. I suppose I could get close to 20 on the hwy at 55 but that's kind of an unknown since I'm unable to keep it at 55 :)

Towing in the steep mountains is 7-8. Towing on flat is more like 9 or a hair more.
 

HorseManAR

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NW Arkansas
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2014
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6.4 Hemi Ram 2500
6.4 here. Couldn't be happier. Best I can tell, 12 or 13 around town. 17 highway, better if you ain't got your foot in it. 8 or 9 towing 10k fiver.

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Caldwell

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Hemi 5.7L
the 6.4L is the better option.

the HP/TQ differences arent much, however the way the power is applied through out the power band seems much better. This motor is designed to be a " Truck Motor ".
 

Jim45498

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Hemi 5.7
Don't know anything about the 6.4 but my Express SWBRC 5.7 tows a bass boat and gets 13-14mpg.
Will get between 19-20 highway mpg.
 

Rich

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Kingston, NY
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Hemi 6.4
I've had my 14 2500 CC with the 6.4 and 3.73 gears for about 2 weeks. 1200 miles on it. Just returned from 400 mile trip pulling a 7000 lb travel trailer + another 1000 lbs or so of related gear, etc. Pulled through a fairly elevated region of Lake Placid & Lake George, NY. I was seeing 7.5 to 8 mpg towing at average highway speed of 65mph. The other 800 miles were mixed driving with a 12 - 13 mpg average to the best of my recollection. As of right now, I've averaged 10 mpg overall. While towing on the highway, the truck stayed in 4th gear most of the time @ 2500 rpm and occasionally shifted into 5th @ 2000 rpm (at 65 mph). Certainly didn't have any issues getting up hills, but I expected slightly better mpg. Any thoughts?
 

SlightlyTweaked

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You never did say how the 5.7 does ?

I have had my 2500 CC 5.7L with 3.73 for 3500 miles now. No towing or hauling but mixed highway and town driving is getting me 14.5 mpg. If I calculate just highway I am about 17.1mpg. Overall I am very happy with the truck. The only thing I regret is not test driving the 6.4L first. I dont plan on doing much hauling only plowing, so I didnt need the extra torque, but now just want it because.
 

Mr. Crowley

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Corpus Christi TX
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2011 2500 4x4 Crew Cab
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5.7Hemi
City driving I've been averaging from 14.5 to 15.5 with my 2011 2500 crew cab 4x4 5.7 hemi with 3.73s.
I've only had it about a month and a half and haven't taken a trip yet to figure the highway mpgs.
 

HillsGreenRam3500

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Snohomish, WA
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2014 Ram mega cab 3500
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Hemi 6.4L
The 5.7l is a very good light duty truck motor but I have to agree with everyone else if your not getting a diesel go with the 6.4l I love mine.
 

rjbar46

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Oklahoma City, OK
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2018 SLT Crew cab 4X4
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Hemi 5.7
There are too many variables to make a decent comparison. Really it apple to oranges, you can’t compare them.
It really boils down to what you need your truck for. Like several have said here they pull rather large 5th wheels. For someone like me who rarely pulls anything and occasionally uses the bed, the 5.7 is just fine. I get 20 mpg on the highway and 16 around town in my 5.7, 8 speed with the 3:21 rear end.
That 6.4L would be a lot better for pulling with a 2500.
 

mowin

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upstate ny
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2017 3500 SRW
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6.4 hemi
My theory is, if you NEED a 2500, get the 6.4. Love mine. 14 around town, as high as 17.5 highway. All hand calculated
 
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Kidder

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Hemi 5.7, eTorque
Just get a Cummins.
Better mileage than both.

And how long will it take to get the money back on the high price of getting into a Cummins vs buying a 6.4 for those that use it for lighter duty?
 

Tuffguy707

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6.7 cummins
And how long will it take to get the money back on the high price of getting into a Cummins vs buying a 6.4 for those that use it for lighter duty?

To answer this question just wait till you sell it or trade it in, you will get all if not more of your money back on the cummins. for example I traded my 07 with the 5.9 cummins in and the dealer gave me $30k for it with 120k miles on it and the sticker was only $39 at the time. So i lost $9k in 6 yrs and 120k miles. what would a gas engine loose, oh I can also answer that question, buddy of mine had the same truck with 80k miles on it and could only get $19k in trade in.
 
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