Newbie in need of advise....5.9L verses 6.7L inquiry

[SteveFortune]

5.9L verses 6.7L inquiry...which is the better engine???
I am looking to buy a Ram 3500 Dually...... The tow limits are close on each....There are just so many more of the 5.9L to choose from than the 6.7L.... Which is the better engine... I know the gear ratio has alot to do with the towing... however, it seems there are more of the 3.73:1 than there are the 4.10:1...... will i be ok with the 5.9L/3.73:1 as long as i am within or close to being within the limits.....

[welderman]

Hello I have had both engines In in the past and am currently using two 6.7L in my welding business one is a 2010 with 3.73 and the other is a 2014 with 4.10 and the Aisin tranny. They both are strong pullers, but they also have pollution systems.one is a dpf ,and the other Def .The 5.9L have no pollution system, and get better fuel mileage .My personal opinion is to stay away from the 2007 to 2012 6.7 because of dpf problems and terrible fuel mileage I had to delete all of the system to get it to run properly without constant trips to dealership. So far the new truck with Def system is working amazing ,and can tow 30000lbs with the 4.10 set up ,and is very quiet as well also no diesel smell from exhaust😧 hope this helps ya

[TDI-Minnie]

I think the 5.9 sounds better than any engine on the road.
But I have a 2012 6.7L and it's awesome.
Welderman makes a point about the DPF, which can be an issue if you let them idle excessively, which you should NOT do with any engine.
Now, the question is really one only you can answer. If you are mechanical and like to tinker on your truck, you can delete the emissions stuff off the DPF equipped 6.7L. Then you have a newer, higher power engine with all the upside of the 5.9.

You can not do this on the 2013+

But if you don't like to tinker or your state has emissions requirements for diesels, the later 6.7 with DEF is probably better.

I bought the 2012 used specifically because they can be "deleted" and have the High output with 800lbft.

The most important part to delete is the EGR, which the current Cummins still has! This Exhaust Gas Recirculator suck soot particles back into the combustion cycle, which is AWFUL for the engine. It scores the cylinder walls, increases exhaust gas temperature and requires a restrictive throttle body.

All the newer diesels have EGRs so that's a universal problem, until you delete.

[Cummins12V98]

Buy a new 15 off the lot, there are great discounts out there be sure to get an Aisin trans. More power and lower starting gears get the load moving easily. They are towing machines.

The 5.9 is a great engine but has a 4 speed trans. 6 speeds makes a world of difference when towing!

Rear air ride is great also. 4:10's will get the most towing capacity. I am extremely happy with my 4:10's and Aisin/6.7 combo.

The oil contamination is not a big deal any longer with the 13 and newer 6.7's the oil change interval is up to 15K now and the oil actually stays clean for a long tome compared to my 11 HO 6.7.

Truck and RV combined 32,540#

15,040 sitting on the 6 truck tires. Can't come close to that with a 5.9 Dually.

[Wild Card]

Originally Posted by TDI-Minnie

I think the 5.9 sounds better than any engine on the road.
But I have a 2012 6.7L and it's awesome.
Welderman makes a point about the DPF, which can be an issue if you let them idle excessively, which you should NOT do with any engine.
Now, the question is really one only you can answer. If you are mechanical and like to tinker on your truck, you can delete the emissions stuff off the DPF equipped 6.7L. Then you have a newer, higher power engine with all the upside of the 5.9.

You can not do this on the 2013+

But if you don't like to tinker or your state has emissions requirements for diesels, the later 6.7 with DEF is probably better.

I bought the 2012 used specifically because they can be "deleted" and have the High output with 800lbft.

The most important part to delete is the EGR, which the current Cummins still has! This Exhaust Gas Recirculator suck soot particles back into the combustion cycle, which is AWFUL for the engine. It scores the cylinder walls, increases exhaust gas temperature and requires a restrictive throttle body.

All the newer diesels have EGRs so that's a universal problem, until you delete.

Above you said you can not do this on 13'+? If your talking about delete...you sure can.

[chaps2018]

The fuel tank size/range (35gal vs 32) and mileage are keeping me from looking beyond the 5.9L ! I get 12mpg hauling 10k trailer in the mountains. 21mpg empty. The thing is a hauling machine. It is a very well understood and mature engine.

[TDI-Minnie]

I get 24mpg empty on the highway, never below 18.5mpg in town. 15mpg towing, but my trailer is lighter.
Tank is 35 gallon. I have no problem going 650-700 miles on road trips.

[TDI-Minnie]

Originally Posted by Wild Card

Above you said you can not do this on 13'+? If your talking about delete...you sure can.

You may be correct. It's been while since I looked, but I there were no tuners available for DEF delete.

[Cummins12V98]

Originally Posted by TDI-Minnie

I get 24mpg empty on the highway, never below 18.5mpg in town. 15mpg towing, but my trailer is lighter.
Tank is 35 gallon. I have no problem going 650-700 miles on road trips.

Hand calc or lie O meter?

Not calling you a liar but those numbers are extremely high for a 2012.

[Wild Card]

Originally Posted by TDI-Minnie

You may be correct. It's been while since I looked, but I there were no tuners available for DEF delete.

$2200, will delete all emissions def,egr, block off, exhaust to replace dpf and a tuner...off road use only

My thoughts are this. 07.5 to 2013 without def, delete...they use fuel to regeneration and suck in the mp range. Mine is Rams problem for 5yrs, 100k miles. After that if I have and issue I will delete.

[TDI-Minnie]

Originally Posted by Cummins12V98

Hand calc or lie O meter?

Not calling you a liar but those numbers are extremely high for a 2012.

Deleting made a big difference.
2wd, 3.73, tonneau bed cover
No added power from the tuner.

On long road trips, I'm always around 650 miles on the tank. I don't usually go too deep into the reserve.

[TDI-Minnie]

Originally Posted by Wild Card

$2200, will delete all emissions def,egr, block off, exhaust to replace dpf and a tuner...off road use only

My thoughts are this. 07.5 to 2013 without def, delete...they use fuel to regeneration and suck in the mp range. Mine is Rams problem for 5yrs, 100k miles. After that if I have and issue I will delete.

The cost to delete my truck was around $1k for tuner and parts. Did the work myself in one afternoon

The fuel used in regeneration is minimal. The mpg gained from deleting is 20%, which is significant. But the point of deleting (for me) was the added health of the engine through lower egt and no soot getting back into the engine.

[chertz]

Curious... what are the ramifications for deleted trucks to sell or trade them in? I have heard most dealers won't touch a deleted truck. Anyone try it yet?

[Cummins12V98]

Originally Posted by chertz

Curious... what are the ramifications for deleted trucks to sell or trade them in? I have heard most dealers won't touch a deleted truck. Anyone try it yet?

Very true, ya better save all the parts!



I asked earlier if the awesome improved mileage reports were hand calc and did not get an answer. On the TDR the original and well respected RAM/Cummins forum if you read the results of deleting there is an improvement but not as much as some claim. The computer will give false numbers after the deleting from what I have read.

Bottom line you most likely will NEVER recoup the cost of the deletes. Much cheaper to leave stock and change the oil more often or better yet install a Bi-Pass oil filtration system.

Remember doing any type of modification can and will destroy your engine/drivetrain warranty.

So repeat after me "I am my own warranty station" !!!