MPG Increase with a Tuner

[Cliffman]

2018 6.7 bone stock. I'm considering a tuner just to increase fuel mileage. Currently getting 8.5 - 9.5. Looking for input from others who have done this. What would be your MPG increase when pulling heavy 5er. Thanks in advance.

 

[AEdelheit]

Just out of curiosity how many miles are on your truck? I know the mileage typically improves once the engine is broken in, also what is the actual weight of the 5er?

 

[lpennock]

Are you ready to give up your drive train warranty? tuner would be problematic if you have engine issues.

 

[Jim W]

I am speaking from a little experience when using a tuner/programmer (Smarty S67) and towing a 5er. Do not expect any big mileage improvements when towing. I have over 11 years of data with the first year as stock to set a baseline. I towed my 5er a 2006 Summit Ridge Ameri-Camp in 2008 with the stock engine, my fuel mileage was between 9 and 10 MPG's. I deleted in 2009 and became my own warranty station, my towing fuel mileage with the same trailer was now between 10 and 11 MPGs.

I have since upgraded to a different camper a 2016 Cedar Creek 34RL, which is like towing anchor behind the truck do to the wind resistance (13'-6" tall). My fuel mileage over four years of ownership (purchased new in 2015) varies between a low of 8.5 (40 MPH headwind) to a high of 12 MPG's. Mainly the fuel mileage is around around 10 to 11 MPG's.

With your truck and the SCR system on it, I would leave it stock unless you want to spend an additional $1,000 to $2,0000 to gain about 2 miles per gallon improvement.

 

[DHayden]

Mileage gains are "usually" made by increasing timing. If you are towing a heavy 5er you will not want to increase timing and probably not more than a 30hp tune. Dropping speed to 65 or even 60 is the best mileage gainer. You may have heard all of this already but its my .02

 

[SnoKing]

What he ^^^ said, slowing down will do more to improve mileage than anything else. At 8.5-9.5 you must be towing at 70 +/-!

 

[Cliffman]

Just out of curiosity how many miles are on your truck? I know the mileage typically improves once the engine is broken in, also what is the actual weight of the 5er?

15k on the clock

 

[Cliffman]

Are you ready to give up your drive train warranty? tuner would be problematic if you have engine issues.

Yup...

 

[Cliffman]

What he ^^^ said, slowing down will do more to improve mileage than anything else. At 8.5-9.5 you must be towing at 70 +/-!

I pull at 62-65

 

[DHayden]

You should still see some mpg increase coming your way. A lot of people have said they did not get max mileage until 25k-28k miles on the clock. Of course that does not mean its a fact, but you can keep your fingers crossed.

 

[TFucili]

My '05 made a small mpg gain at 10K, and then at 30K. Which trans and rear gears do you have? To be honest, I think the only mpg gain with a tuner will be from the lightening of your wallet.

 

[Shiner]

My '05 made a small mpg gain at 10K, and then at 30K. Which trans and rear gears do you have? To be honest, I think the only mpg gain with a tuner will be from the lightening of your wallet.

LOL!!! Good 1!

 

[cerberusiam]

Need to know truck configuration, trans gears, number of wheels, tire size, etc. A tuner will make more of a difference empty than loaded. You should still see an increase loaded if you have a decent gear ratio. You are right there with everyone else towing heavy.

 

[Cliffman]

My '05 made a small mpg gain at 10K, and then at 30K. Which trans and rear gears do you have? To be honest, I think the only mpg gain with a tuner will be from the lightening of your wallet.

4:10's with the AISIN transmission.

 

[cerberusiam]

Assuming it is a dually? What gear are you towing in? What rpms are you running at that point? You have enough gear that a taller tire may help some. Assuming most of the towing is at steady speed and not a lot of stop and go, a tuner may help that a bit by cleaning up the emissions tuning for more efficient combustion.

 

[p-Bar]

The 3rd gens have a "sweet spot" of 1850 RPM . Where is it at on the 4th Gens?

 

[Wiredawg]

my sweet spot on my 2017 5500 is 2100 rpm. been that way for all my pulling trucks, likely due to gearing, axle ratios, and driving 65 and 70. I ran tuners and/or chips to get a little more grunt and to match hp/tq on my C&Cs to the HO pickups. I have chip on my 2017 and like it. About .6 mpg improvement but better low end tq/hp.
BTW, running avg with this truck is 9.1 mpg combined. 98% is towing. My deleting days are over, too much work and some risk govt will start enforcement and fines.
Cheers, Ron

 

[Cummins12V98]

AISIN with 4.10's towing 33k combined WestCoast Towing I hand calc average 9.5. The AISIN always has the correct gear as long as you use TH and EB.

I'm betting if I deleted my "TOWING" mileage would not change one bit!

 

[Cliffman]

Assuming it is a dually? What gear are you towing in? What rpms are you running at that point? You have enough gear that a taller tire may help some. Assuming most of the towing is at steady speed and not a lot of stop and go, a tuner may help that a bit by cleaning up the emissions tuning for more efficient combustion.

Tow haul mode will shift into 6th gear when there's no load demand. My rig weighs 15k. And yes, it's a dually. Don't recall the RPM's but I don't pull past 65 MPH.

 

[TFucili]

Have you scaled your combo, or is that based on mfr specs? You may have to experiment a couple mph faster/slower to find the best for your combination.