For a Duramax tuner bought with fuel mileage in mind, begin with exact truck fitment and emissions documentation, then decide whether its other features justify the cost. Two options with documented applications are the Edge Evolution CTS3 85400-200 for specified older 6.6-liter trucks and the Banks Derringer High Output 67106/67126 for specified 2020–2022 L5P trucks. Neither is a guaranteed fuel-saving purchase.
This shortlist compares manufacturer documentation and California Air Resources Board executive orders. It does not rank measured MPG gains, claim hands-on testing or extend one truck’s compatibility to every Duramax. A diagnostic scanner, throttle-response controller or gasoline AFM/DFM disabler is not interchangeable with either exact tuner below.
Two tuner options to compare by truck
| Product | Documented application | What it does | Emissions document |
|---|---|---|---|
| Edge Evolution CTS3, part 85400-200 | 2001–2016 Chevrolet/GMC Silverado/Sierra 2500 and 3500, 6.6L Duramax; EO also lists 2011–2016 GMC Denali 2500/3500 | ECU flash tuning with an in-cab touchscreen monitor | CARB EO D-802-13, subject to the listed applications and approved configuration |
| Banks Derringer High Output, 67106 or 67126 | 2020–2022 Chevrolet/GMC Silverado/Sierra 2500/3500, 6.6L L5P, with the test groups listed below | Inline tuning with iDash Pro or iDash Data Pro | CARB EO D-161-167, subject to the listed applications and approved configuration |
Edge Evolution CTS3 85400-200: for listed older 6.6-liter trucks
The Edge Evolution CTS3 85400-200 combines a 5-inch touchscreen with flash tuning, monitoring, data logging and Wi-Fi updates. Edge describes settings for daily driving, towing and performance. It is a candidate for an owner who wants tuning and an in-cab display together, provided the exact truck and calibration are supported.
The actual D-802-13 order names part 85400-200 and the 2001–2016 Chevrolet/GMC Silverado/Sierra 2500/3500 6.6L Duramax applications; it also lists 2011–2016 GMC Denali 2500/3500. The order describes reprogramming the stock ECU and says emission-related data files cannot be modified by the end user. Its exemption depends on the specified tunes and conditions.
Do not substitute a similarly named CTS3 product or assume this part covers newer L5P trucks, a 3.0-liter Duramax, a van or a different chassis. Edge states that this product does not support removal of emissions equipment. The manufacturer also explains that changing tunes requires reflashing the PCM, so it is not an on-the-fly power-level switch.
- Reason to buy: one device for approved flash tuning and a visible monitoring interface on a confirmed supported truck.
- Reason to pause: if the purchase only makes financial sense after an assumed MPG increase, or if the seller cannot verify support for the truck’s current calibration.
Banks Derringer HO 67106/67126: for the listed 2020–2022 L5P applications
The Banks Derringer High Output kit takes an inline approach. Part 67106 includes iDash Pro without data logging; part 67126 includes iDash Data Pro with logging. Banks lists six selectable power levels and an OBD-II connection that supplies vehicle data to the system. The gauge mount is not included.
CARB EO D-161-167 specifically lists 67106 and 67126 for 2020–2022 Chevrolet/GMC Silverado/Sierra 2500/3500 with a 6.6-liter engine. The listed emissions test groups are LGMXD06.6375, LGMXD06.6385, MGMXD06.6375, MGMXD06.6385, NGMXD06.6375 and NGMXD06.6385. Compare the complete test-group code on your truck’s emissions label with the order, not just the displacement or badge.
Banks supplies separate installation instructions for single- and dual-alternator trucks. Confirm the truck’s configuration and the exact complete kit before ordering. This is an under-hood harness installation as well as an in-cab display installation; it is a different commitment from plugging in a basic code reader.
The 67106/67126 application should not be stretched to a different model year merely because another Derringer kit appears on the same executive order. Use the correct part, approved configuration and current manufacturer instructions. The order is not an endorsement of MPG gains or a guarantee about the vehicle manufacturer’s warranty.
- Reason to buy: an inline tuner and iDash display for a confirmed matching L5P, with the logging version available if recording vehicle data matters to you.
- Reason to pause: the extra mounting and installation work, unresolved emissions-label matching, or expectations that advertised horsepower gains necessarily reduce fuel use.
What emissions documentation does and does not establish
The EPA explains that the Clean Air Act prohibits tampering with emissions controls and the manufacture, sale and installation of devices intended to defeat them. Controls include hardware and engine calibrations. Keeping the stock exhaust visibly in place is therefore not the only question when evaluating a tune.
For these picks, keep all required emissions equipment functional and use only the configuration covered by the applicable documentation. Reject an offer that depends on disabling emissions controls or their diagnostics. An “off-road” description or a promise of improved mileage is not a substitute for documented compliance.
A CARB executive order covers the specified product and vehicle application under its conditions. Both orders warn that changes adversely affecting the emissions system invalidate the exemption, and both disclaim endorsement of claimed benefits. Do not translate an EO into “EPA approved,” guaranteed savings or blanket warranty protection.
Make the fuel-mileage decision before buying
- Collect the exact truck information. Record model year, model, engine, emissions test group, existing modifications and current calibration information. Have the manufacturer or installer confirm the exact part and supported software, and check the current executive order and application guide.
- Establish your own baseline. Record miles driven and gallons added over several comparable fill-ups. Compare similar routes, loads, speeds and weather rather than one unusually good tank or an isolated dashboard number. If consumption has unexpectedly changed, investigate the underlying problem before buying a tuner.
- Count the complete cost. Include the tuner, required mount or accessories, installation and any specified licensing. Buy because the verified features are worthwhile at that total cost; budget with zero assumed fuel savings.
- Check support and return terms. Confirm what happens if the current calibration is unsupported and whether unlocking, pairing or installing affects return eligibility. Ask about vehicle-warranty implications separately from the tuner’s own warranty.
Frequently asked questions
Which tuner will give my Duramax the best MPG?
The evidence here does not establish a comparative MPG winner. These are fitment-specific tuning options, not demonstrated fuel-savings rankings. Neither CARB order certifies fuel-economy benefits, so do not assume the purchase will pay for itself.
Can I use these with removed emissions equipment?
That is outside this shortlist’s approved-use conditions. Edge explicitly says the product does not support emissions-equipment removal. EPA’s prohibition on tampering applies to required controls; choose a documented compliant configuration with the equipment intact and functional.
Is a scan tool or throttle controller a cheaper equivalent?
Choose according to the function you need. The Edge is a flash tuner and monitor; the Banks is an inline tuner with an iDash display. A product that only reads diagnostic information or changes pedal response has not thereby demonstrated equivalent tuning or a fuel-economy benefit.
