6.7L Cummins Forum

I'm picking up my 2011 Ram 2500 6.7L , auto,with 410 rears today. This will be my first diesel pickup but have put over 2 million miles on N14+ and now ISX motors. I'm concerned with the poor fuel economy compared to the 5.9L or Duramax, and high fuel prices and forecast of $5 a gal diesel by summer.
I've been friends with my dealer for 30 years and asked him what would void my engine warrranty as I was wanting to put cold airbox, exhaust and tuner/programmer for increased mpg's. He said not supposed to put anything, but assured me he could get my truck warranteed as I want to increase mpg 's starting on my 2nd or 3rd tank after I get somewhat of a baseline mpg for comparison.
So here's the question I post to you members and any and all help will be greatly appreciated, thank you in advance. My question is which brand of airbox, 5'' exhaust and tuner/programmer work best and especially when used together on the 6.7 Cummins. I'm mainly looking for max increase in fuel mileage could care less about hp gains.
My truck has the 6 speed auto and 410 rears and plan on lifting it 6'' and puttting 35's on it as soon as it's ready for new tires.Thanks for any and all advice. Brad

First of all, welcome aboard. Second, this is not the place for this question. You should have started a separate thread for the technical questions. Will fix that.

I will be blunt, If you are concerned with mileage, then doing a 6 inch will hurt you badly !! You can lose easily 1 to 3 MPG on that alone. 35's will not help either.

What is your driving model ? Are you mostly highway or city ? With a 4.10 rear end on my 4x4 dually and 19.5 tire setup, I equal 33's. Mileage in town went from 13.5 to 10.5, highway mileage went up. However I am setup to tow heavy and all highway usage for that.

Search the forums for CAI, we have discussed that alot here. Several good brands, key point, CAI need to draw cold from outside the truck, not via the engine compartment.

Tuner will void warranty, end of discussion. Dealer on a warranty claim has to file paperwork that is reviewed by Corporate office. In the review process, data from the ECU and/or TCU shows turner modification, dealer will not get paid for the service. So them saying your covered is BS. Got it in writing ? Turners for mileage only have a habit of trying to lean things out, not good for a engine that uses its fuel for lubrication properties.

If you want mileage and not planning on using the 4.10 as designed (heavy towing), then change the rear end to 3.73, that will help a lot. Stay with smaller tires, but industrial material (harder and less rolling resistance). Do not left that will cause tons of under carriage drag, do not a 2" front level left either (that costs around 1 MPG also). Also, our engines are post injection process for smog, no urea. So when you factor mileage for comparison, you have to factor cost per miles on the urea and include that. On non C&C, we do not have that diesel is used for smog filtering.

Hope that helps. I will move this post to it own section so the discussion can continue and be in topic.

Cheers.

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Figured out how to move posts around and moved it here which I think is a better fit and than the new member section. If wrong, please let me now and can move it again.

Lets get the discussion rolling and see what we can come up based on existing experieces

Cheers all.

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Was looking for advice on what brands work best on the 6.7L. Is it Bully Dog, Banks,Smarty, Superchips,Edge, AFE, Airraid, K+N , so I don't throw away money from the get go , not an opinion not to lift my truck. Thanks anyway

On cold air intakes:

We have folks with ...

Voltant with review at Volant CAI Install and Review For the 6.7L Cummins From what I have seen here, members using it have been pleased.

Banks w/scoop however I can not find a review, must be searching wrong ... I have that installed in my truck and have seen a slight performance and mileage increase. I have been very pleased with my Banks setup, always been a fan of K&N filters, 30+ years using it with no issues.

Many have modified the OEM airbox for a scoop and 3rd party filter. Folks have had good results from that. Very little cost and lots of gain.

S&B has a new unit out that is a clone of the Banks setup. Have not heard much about it in terms of people actually using it even in other forums.

On Tuners ...

We have some folks running Edge w/Attitude. Lots of pros on this one, no ecu changes and not detectable when removed. Folks here seem to be pleased with it.

We have some folks running Bully. I have tried it myself also (I had problems with early on), others have had good results. It does leave a well known traces when removed if concerned with warranty. May reload mine with new update code and try again, 10 MPG in town currently is killing me.

We have several folks running Smarty. Smarty seems to have the best overall results. I plan to order one soon to try out myself to try setting people have been publishing.

The reason for mentioning the lift is because you seemed concern with mileage and I know of folks that have done comparisons on mileage with and without lifts and the lifts cost mileage. Even the 2 inch level costs mileage and I have noticed that with my truck on the highway. However in my case, its an air lift in the front, so now on the highway, I drop the front back to OEM level and able to pick up a few 10th per gallon.

Another area you can pick mileage and less wear / tear is doing a hub conversion in the front. Go for manual hubs, that can add up 1.5 MPG gain and less service on the front end (double gain). That helped me out.

I know you mentioned not concerned about performance, but it does add to some overall mileage ...

- better flowing horn (Shibbly makes one that is full smog legal). This horn allows better volume of air to move through.

- grid heater relocation. Removing the grid heater from the intake manifold and relocating it before the butterfly valve on the horn removes the restriction that exists and gets worse as soot builds up and moves it up stream. Now soot can not collect and restrict flow.

A tuner is not going to add lots of mileage increase, but anything helps. What ever tuner you use, make sure you have a good set of gauges. It will help save your rig when things start to south. If you keep all your smog in place and have a tuner, watch your DPF loading, EGT, and track your regens. Those will also help with mileage, if lots of regen start happening, your blowing lots of extra diesel out the exhaust.

Hope that helps.

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6" lift will make 35's look small on a Dodge. If you lift 6" you'll need 37's atleast. Any tuner you install on a 6.7 Cummins leaves a footprint, as soon as you download a tune, (change ECM/TCM settings), your powertrain warranty will be void. Dealership can hide the tuner footprint to a certain point. But if problems get serious enough to involve Dodge Tech Reps, they WILL find the footprint left by the tuner and void your warranty. This past summer I had problems with my DPF clogging, luckily caused by injectors and not modifications that I had made. Dealership ended up spending around $16,000 bucks at their cost on warranty work, I don't know about you but I could not have been able to afford to spend that due to the $1500 in exhaust, intake, and Bully Dog that I had installed.

With 35" or larger tires, 5" exhaust, and a cold air intake. You should plan for 10-12 MPG in town and 14-16 on the highway.

Mine will probably remain stock until I trade it for the 2013 model (says she!)
I am looking at options already. No issues, no problems with mine at 60K miles.

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07.5 3500 Quad, SRW, 4X4, Laramie, Leathered, Dark Metallic Gray, 6.7, 68RFE, 20K Reese, Ride Rite's, 2 Viair air compressors, Bully steps, Kleinn Locomotive air horns (5 in all), Billet polished locking fuel door, 'A' pillar mount Auto Meter Pryo, PML X-deep trans pan
06 Durango 285 RL 5'er Lifted by KZ

operating an 08 3500, pulling 35' gooseneck. all stock except for 3 year old bullydog. just the truck on freeway i get 22 mpg. hauling trailer empty,,,15-16 mpg...trailer with under 5000 lbs...12 mpg. over 5000...8-10 mpg. i have 205,000 miles on it. wish i had found this site when truck was new. never changed ccv filter until 150,000. now having major surgery on it. dpf plugged up. blown head gasket. egr on the blink. never cleaned it. blowing lots of black smoke.. but it'll still outperform anything on the road.

update: just came from mechanic. no blown head gasket...hole blown in rear of manifold. mech says i shouldn't run my bullydog on "tow" while in the mountains. egt gets too hot. egr is off being cleaned, as is dpf. my poor truck is sick(crying)

That sucks, everyone who owns a diesel should have some sort of EGT Gauge especially with a programmer.

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2007.5 Dodge Ram 3500 HD,QC, 6.7L Cummins, 6speed Auto, 4X4, Bighorn Edition.
Click for installs: Carr Steps PML Diff Cover Edge Juice with Attitude Volant Intake Hankook ATM RF10