Duramax Tuners?

[Pigpen29]

I have a 2013 GMC Duramax diesel dually...those of you motor heads out there that use a tuner, what are you using and why? What do you like or dislike about it? My first diesel and really know nothing about tuners. I'm not super interested in getting crazy power, more interested in getting a little better MPG. I currently get 10 miles a gallon towing 42' fifth wheel that is 12,500 dry. Thanks in advance for comments!

[NMWildcat]

In my opinion, a tuner will not help you improve your mpg significantly while towing, unless it is combined with a full/partial delete, or upgraded components. And used incorrectly, a tuner can cause more harm than good.

10mpg while towing that rig isn't that bad

With your level of experience, I would go talk to a good diesel performance shop. You can spend a LOT of $$$, very quickly, and they might be able to provide help in where to spend it most effectively. Good luck and have fun!!!

[calgarycampers]

I agree with NMWildcat. Tuner will not improve your factory components and will cause grief down the road. I have not modded my 07 2500 RAM and have had great power, mileage and performance. I killed my first one after a tuner mod and took out all my injectors in three years.

[Jim34RL]

Will I disagree. I have had a programmer on my truck since Mid-09 it is now early 18. I have had better performance and fuel mileage with my SmartyS67 than without.
My fuel mileage in 2008 when towing a much smaller 5th wheel was a low of 9.43MPG to a high of 10.7MPG when towing that unit.

I am now towing a 13.5 Tall 34RL Cedar Creek a much heavier and taller unit. My mileage is now a low of 11.59MPG to a high of 13.35MPG this last year.

I tow with my SmartyS67 set to CatCHER level 3 for towing.

I would look into EFI Live with an Edge Insight to monitor the engine parameters for your Duramax. If you do this right and keep your power down the engine and transmission will last just as long as a stock engine will last.

[NMWildcat]

In my mind, a one to two mpg increase is not significant for the cost of a tuner. I do agree with Jim34rl that a tuner can improve performance w/o any harm to drivetrain, but you need to know what you are doing and have equipment to monitor. All this is expensive for a small gain. That's why a beginner should trust a performance shop to guide and educate them.

[Pigpen29]

Great info so far...I would love to go to a performance diesel shop but there are not within a couple hours that I know of. Gonna look into that further though. Keep the info coming!

[Helmsey]

I have emissions on tuning from "Idaho Rob" at ATP truck on my 2015 and couldn't be happier. We tow a 5er that weigh in around 15k and we get around 10MPG towing it around. He tuned my older Duramax and I was extremely happy with it, so I went to him with my LML. He has a nice write up on their blog about his daily driver LML that has emissions in tact that he is using for testing. I have 3 tunes from him; mild, tow, and performance. Normally the truck keeps the performance tune on it for every day driving, i think its around 110HP over stock. I swap to the tow tune when anything is hooked up to the truck and it works fantastic.

[Jim34RL]

Originally Posted by NMWildcat

In my mind, a one to two mpg increase is not significant for the cost of a tuner. I do agree with Jim34rl that a tuner can improve performance w/o any harm to drivetrain, but you need to know what you are doing and have equipment to monitor. All this is expensive for a small gain. That's why a beginner should trust a performance shop to guide and educate them.

The improvement is just not in towing but in normal day to day driving.
As an example when I did not have the tuner on my truck. I drove a total of 12,706 miles and filled up with 1,096 gallons of diesel for a average 11.59 MPG. Now that the tuner has been installed using the approximate same mileage for a year, 12,929 miles and I filled up with 934 gallons for a yearly average of 13.84 MPG. I have improved at least 2 MPG to as much as 4 MPG depending if I am on the highway without the trailer or towing.

I was regening about every 200 to 300 miles so, as you can see I have saved 162 gallons of diesel fuel for one year. This is a savings of $448 at least for this similar mileage usage using $2.77 a gallon as a cost bases. I do have 10 years of data to back up these numbers.

[Pigpen29]

Originally Posted by Helmsey

I have emissions on tuning from "Idaho Rob" at ATP truck on my 2015 and couldn't be happier. We tow a 5er that weigh in around 15k and we get around 10MPG towing it around. He tuned my older Duramax and I was extremely happy with it, so I went to him with my LML. He has a nice write up on their blog about his daily driver LML that has emissions in tact that he is using for testing. I have 3 tunes from him; mild, tow, and performance. Normally the truck keeps the performance tune on it for every day driving, i think its around 110HP over stock. I swap to the tow tune when anything is hooked up to the truck and it works fantastic.

Great info and site...the base line tune they have is probably what I'm looking for. Keeps the truck stock for about $650. Thanks!

[Pigpen29]

Originally Posted by Jim34RL

The improvement is just not in towing but in normal day to day driving.
As an example when I did not have the tuner on my truck. I drove a total of 12,706 miles and filled up with 1,096 gallons of diesel for a average 11.59 MPG. Now that the tuner has been installed using the approximate same mileage for a year, 12,929 miles and I filled up with 934 gallons for a yearly average of 13.84 MPG. I have improved at least 2 MPG to as much as 4 MPG depending if I am on the highway without the trailer or towing.

I was regening about every 200 to 300 miles so, as you can see I have saved 162 gallons of diesel fuel for one year. This is a savings of $448 at least for this similar mileage usage using $2.77 a gallon as a cost bases. I do have 10 years of data to back up these numbers.

Great info and thanks for keeping all the data over the years! That is something that I would never have the patience to do! lol

[Captain America]

I went with EFI Live. I found a shop 45 minutes away that does custom EFI tunes. He has a dyno and will make a custom tune based on your perimeters.

I told him what factory and aftermarket components on my truck and I wanted a safe tune that will increase MPG and help with towing. He put my truck on the dyno and got a baseline. He loaded up a base tune he uses for hotshoters and customized it for my truck. It took him about 3 hours and 4 pulls on the dyno to dial the tune in. He wanted to keep torque around a safe 675 ftlb for the Allison.


I have a single EFI Live tune, but you can get 5 tunes loaded to your ECM and switch them on the fly. With the Allison being a learning transmission, if you switch tunes it will have to learn new shift points and driving habit. I did not want to have to deal with that.

[Helmsey]

Originally Posted by Captain America

I have a single EFI Live tune, but you can get 5 tunes loaded to your ECM and switch them on the fly.

It's not as easy on the LML's as it is the LBZ's to switch on the fly, they won't user the DSP5. I have to reprogram each time I change with my Autocal whice sounds worse than it is. It takes about 2 minutes and 45 seconds to complete the flash and be back up and running again. However I sure do miss the DSP5 that I had on my LLY.