5.7 Hemi VS 6.4 Hemi

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loveracing1988

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I am definitely looking into the 6.4L instead of the 6.7L CTD for our retirement tow vehicle! Just need the right Transmission & gearing combo.

Just to many dam issues with the egr & def systems occurring.
It's only going to get worse! With more & more restrictions & regulations being handed out.
They said the same thing back in the 70's with catalytic converters...

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SyN

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Well with 3 co-workers having these issues constantly with their 6.7L! & kicking & yelling every second of it! I honestly want no part of it!

These 2 systems are a bit more complex then a kitty.

We will see! Still have 6 more months to decide & as well hear & see more horror stories.
 

Rockit

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just googled Cummins 6.7 DEF problems and it listed 61,900 pages of issues , DEF problems suck as the dealer can only keep it to Govt specs .
 
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SyN

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^^^They are not serious internal issues but the dam thing will put you in limp mode and leave you & your family stranded.

I work within a plant that creates this DEF from UREA ---> All from Natural Gas!
It is a major pain in the A$$. It salts out so easy and causes major plug age in most of the smaller flow orifices & valves. Basically the same issue with the DEF injector.

Each line it flows in has to be steam traced to keep it above 45-50*F so it does not salt out solid.
Each line has to be totally flushed with demin water after trucks are loaded if the line will not be in operation again for 24hrs.
 
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69GWC

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Yeah its a junk system for sure.

EPA has ruined diesels IMO. Is why I went back to the 1500 well and I did not need the torque from the diesel any longer and the 6.4 has a terrible transmission...lol
 

SyN

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I just got through having a text message session with two of them it seems to be the DEF thanks have three heating elements inside.

These heating elements keep going bad and shutting off.
Max has had to have his truck towed in 2 times already within the last year and a half.
He is just about had enough and is possibly fixing to have the whole system removed as well as the EGR system. Which he says will cost him about $1700.

Like I posted if I can get the right combination of transmission and rear end gears with the 6.4L.
I might have no need for the larger more powerful 6.7L CTD.

We will cross that bridge in about 6 more months.
 
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AFMoulton

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I just got through having a text message session with two of them it seems to be the DEF thanks have three heating elements inside.

These heating elements keep going bad and shutting off.
Max has had to have his truck towed in 2 times already within the last year and a half.
He is just about had enough and is possibly fixing to have the whole system removed as well as the EGR system. Which he says will cost him about $1700.

Like I posted if I can get the right combination of transmission and rear end gears with the 6.4L.
I might have no need for the larger more powerful 6.7L CTD.

We will cross that bridge in about 6 more months.



SyN what is the major issues with the 66RFE? I'm currently looking at 2500/3500 trucks and I am back and forth on 6.4 vs 6.7 and all the issues. I would like the diesel for the towing advantages especially with the trailers we are looking at, but I'm hesitant about the emissions crap, but if the 66RFE has issues that will make my decision for me.

My Brother-in-law has a '12 2500 and the mechanic told him that every once in a while he needs to take it on the highway and let it burn out the crap in the exhaust.


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SyN

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I am not aware of any major issues.
I just have not read any high praises either.

If at the time of purchasing if NO other Transmission is offered.

I will install a high capacity oil pan w/drain plug & install an in-line spin-on filter kit & run RL ATF. Along with a handful of powerful magnets!

I only know with the 6.4L a properly geared Transmission & Rearend is vital.
The transmission will be the weakest link.

Not for sure how large of 5th wheel the wife is going to pull the trigger on!
We definitely are looking for a toy hauler--->The extra space in the rear is ideal.

Still a lot of research to do.

I feel honestly a properly equipped 2500 6.4L w/4:10 rearend could handle our needs.

Yes I agree these diesels are not created for daily drivers they were created to work hard every day and be on the highway basically pulling loads.

Kat: I do apologize I took this way off topic by bringing in the 6.7L CTD talk!
Back to Topic!!
 
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barr0208

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rumour has it ford maybe putting there 10 speed auto in their hd gassers and maybe in the rams redesign maybe putting there 8 speed with the 6.4 then I will buy a 2500
 

69GWC

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Lol that would be about right, I did not buy a 2500 just because of that crappy transmissions.
The 8sp would make the 2500 6.4 a beast of a truck.
 

meedom

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I gotta say it, if anyone thinks a Ram 2500 gasser is gonna get close to the mileage of a 1500 5.7 they're just crazy. It's physics guys, you're talking about a vehicle that weighs a minimum of 1200 pounds more! The only way it could compare mileage wise is with the 6.7 diesel....
 

tsielski

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I've had two Rams with diesels, and now the 1500/5.7. The 95 2500 with 5.9 Cummins and a 5-speed was a good truck, and even after I hot rodded it (370 injectors, completely recalibrated P7100, larger turbo and a 4" exhaust), it would get ~20 mpg empty on the interstate if I kept the speed to around 70 (3.54 gears). I'd still have it, if it wasn't rusting away, thanks to all the winter salt.
My 2011 3500 SRW with the 6.7 Cummins and 4.10 gears was a much more refined truck, and for the 4 years it was deleted, it was superb. Deleting didn't net the fantastic mileage gains I'd frequently read, but driveability was much improved. As soon as inspections here began looking for diesel emissions equipment (installed & operational), I returned it to stock and drove it for another year. Highway mileage was 16 on a good day. Deleted, it was around 18, both unloaded, not towing. I will say, I towed 16,000# (JD 1010 with a huge Ford backhoe attached, while it was deleted but no additional power to avoid shredding the transmission) for several hundred miles, and that truck handled that load like a pro.

The new diesels do get decent mileage. From what I've read on the TDR, around 20 highway unloaded, but like many have stated, the emissions equipment is complex and has way too many potential failure points, not to mention the eventual need to replace the DPF for $2k+ as the truck ages. Had I a need to tow heavy periodically, I would probably have another diesel.

I thought long and hard about getting a 2500 with the 6.4. However the 3500# enclosed cargo trailer I tow periodically is no issue for my 1500, and the 1/2 ton is way more comfortable. Most often, the only thing this truck hauls around is my butt, and I really didn't need another HD truck to do that. The 1500 has gotten a high of 21+ mpg on the interstate, and thats with 3.92 gears. Towing the trailer it drops to ~ 14, but the trailer is 6' + tall and wind resistance takes its toll. No regrets tho.
 

pcschwenke

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I had a 2015 5.7l with 8 speed and 3:21 gears which got around 20mpg hwy and 15mpg city. Towing a 8klbs it averaged around 11mpg. With my new 2016 3500 with 6.4l and 4:10 gears I get around 15hwy, 11 city, and 9.5 towing. Now where near comparable, but it’s a beast. It’s still being broke in at 6500miles though.
 

Reeb

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I have a 5.7 2500 with 4.10's and I get just under 14mpg empty 50/50 city/Hwy driving.
I get about 9mpg with roughly 6-7000lbs on the hitch hwy driving.
I try not to get too far over 60mph and never under 55mph. I went from the interior of BC to northern Alberta and back. Straight up the Rocky Mtns.


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