Duramax LMM Tuning Guide

Engine tuning is the best performance upgrade for a Duramax LMM. A simple plug-and-play tuner, or custom tuning, can easily add over 100+ horsepower and 200+ torque. Additionally, you get a number of other benefits like increased gas mileage, better towing, transmission tuning capabilities, and a more efficient engine overall.

There are a lot of considerations when it comes to tuning and selecting the right programmer. We’ve tuned LMM’s with everything from EFI Live to HP Tuners to canned tuners like PPE and Edge. In this guide we will walk through some of the tuning basics, performance benefits, and best setups for the Duramax LMM.

Tuning Basics

Of the endless list of mods you could do to your Duramax, a LMM Duramax tuner is one of the most popular. This mod is very cost-effective and does a great job of adding horsepower and torque. Besides plugging in the tuning device, a tuner requires no hardware modifications, making it incredibly easy to install. In addition, tuners are completely reversible, so if you decide to at any time you can remove it and go completely back to stock like nothing.

The purpose of tuning is primarily to boost horsepower and torque and make the truck more responsive. It also boosts towing power considerably. They are great not just for otherwise stock vehicles, but they can also help get the most out of other mods, like a downpipe, intake, or new turbocharger.

Tuners work by either rewriting or manipulating signals from the engine control unit (ECU). On modern cars and trucks, pretty much every aspect of the engine and vehicle are controlled by an onboard ECU. This includes boost pressure, air-to-fuel ratios, ignition timing, camshaft timing, fuel pressure, and more. With a tuner, you can change these parameters to increase boost pressure, increase timing advance, crank up the fuel pressure, and alter air-to-fuel ratios. That will add horsepower and torque, making your LMM a much more powerful and more capable truck.

Duramax LMM Tuning Benefits

• 100+ horsepower
• 200+ lb-ft of torque
• Improved power band
• 2-5mpg increases in fuel economy
• Better towing
• Datalogging
• DTC Troubleshooting and Clearing

By far the biggest benefit to adding a tuner is the big increases in horsepower and torque. Depending on the specific tuner you use, calibration level you select, and the year and model of your Duramax powered vehicle, you can make some serious gains. With a tuner, you can easily gain 100+ horsepower and 200+ lb-ft of torque like it’s nothing. This makes a significant difference in terms of both acceleration and towing, and really transforms your truck.

In addition to having much better peak power, you’ll also notice a significantly larger overall power band. You’ll make more horsepower earlier and it will hold out for longer, meaning a much improved mid-range. Depending on the tune, you can also see some increases in fuel economy by a few mpg, though the more you take advantage of the newfound power the worse mileage you will ultimately get.

In addition to getting better performance, you can also get tunes that prioritize towing. Considering the primary use of most Heavy Duty trucks is going to be hauling and towing, this is a big deal. Gaining more torque makes towing noticeably easier on the LMM Duramax.

Another advantage of getting a handheld tuner is they allow for data monitoring, data logging, and DTC troubleshooting and clearing. If you want to be able to monitor things like boost pressure and diesel particulate filter (DPF) status, a tuner is a great tool that allows you to do those things. Tuners can also read and clear DTC codes, stopping you from paying a shop or buying another device.

Custom Tuning vs. Canned Tuners

There are two options for tuning: getting a device that comes pre-tuned with plug and play maps or getting “custom” tuning via either EFI Live or HP Tuners. The first option is going to be the most affordable and easiest option, utilizing a tuner like the PPE Xcelerator or Edge CTS3.

EFI Live is the best tuning option for the LMM. However, you have to purchase the device plus custom tunes from a tuner. This will end up running you around $1,000 to $1,500 whereas a canned programmer is as cheap as $450.

If you are just looking for some decent power gains and better MPG then getting a canned device is perfect. If you want to maximize performance gains, plan on adding more advanced modifications, or want transmission tuning then EFI Live is the best.

Transmission Tuning

The Allison 1000 that comes mated to the LMM can only handle about 450whp before it starts losing reliability and will need upgrades. If you plan on pushing over 400whp then we highly recommend transmission tuning which will help you maintain reliability up to the upper 400’s.

If you want transmission tuning then you need to go the custom tuning route and get EFI Live or HP Tuners.

Best Duramax LMM Tuning Setups

• EFI Live
• PPE Xcelerator
• Edge Evolutuion CTS3

1) EFI Live with Transmission Tuning

EFI Live is the most precise and capable tuning option for the LMM. It does require you to work with a custom tuner or at least purchase separate tunes from a tuner. But it’s the most capable device and the preferred option for most people looking to really maximize performance and efficiency.

EFI Live is also capable of handling transmission tuning which will run you a few hundred bucks extra but is totally worth it.

Overall, you’re probably looking around $1,000 to $1,500 for a full setup here but it’s the best tuning option around for sure. The one caveat is that it does not come with a fancy monitoring screen, so it’s popular to combine this with an Edge Insight CTS3 which will add another ~$500 to the cost.

Price: $1,000 to $1,500

2) PPE Xcelerator

If you don’t plan on running aggressive power levels or pushing the limit of the Allison 1000 transmission then sticking with a plug-and-play tuner with canned tunes is fine. The best option for this route is getting the PPE Xcelerator which probably has the best preloaded tunes on it out of all available devices.

At just $450 it’s a great value play with great tunes – it gives you all the benefits of tuning without killing the bank. The one caveat to this one as well is that it doesn’t have a nice screen for monitoring. But outside of lacking good monitoring it’s the best budget play here for those not pushing the envelope.

Price: $449.99

3) Edge Evolution CTS3

A good in-between option is the Evolution CTS3. It has some canned tunes on it – they aren’t quite as good as the PPE but they are solid for a stock or lightly modified truck. The benefit you get here is you get a nice touch-screen monitor as well so it’s a good option for both tuning and monitoring.

The CTS3 can’t handle transmission tuning but it is capable of handling custom tuning so this does give you an option to go that route down the road if you’d like. It’s right in the middle price wise as well so it offers a good value with the two-in-one tuning and monitoring plus gives some fliexibility in the event you want some custom tuning down the road. And it all comes in a very nice touch screen 5″ device.

Price: $745.95

View Here: Edge Evolution CTS3

Summary

Overall, adding a tuner is a great way to add horsepower and torque to the Duramax LMM.  Some tunes can even add 2–4 mpg, depending on which calibration you choose. A tuner can completely transform your truck from a spirited ride to an absolute monster in just a few minutes. You can add anywhere from 50–150 horsepower and 50–250 lb-ft of torque without any other hardware modifications, making it by far the most cost effective way to mod your Duramax diesel.

EFI Live is the best tuning option available and can handle both custom and transmission tuning. If you don’t need all the bells and whistles then you can save a few bucks with a PPE Xcelerator or an Edge Evolution CTS3.