Cummins Custom Tuning in 2026
HPTuners or EFILive? SOTF or CSP? Light duty or heavy? Everything you need to know before you spend a dollar — written by the guy who’s done it a few thousand times.
Why Your
Truck Is Lying
To You
Cummins builds some of the most capable diesel engines in the world. Then OEM manufacturers, fleet managers, and government regulators spend considerable effort making sure you never know that.
Your truck left the factory with its power rating set somewhere in the lower half of what the engine is mechanically capable of. The Cummins engineers built it for one specification. The RV manufacturer, chassis builder, or Ram corporate decided what you’d actually feel at the throttle — and they almost always leaned conservative. Insurance considerations. Warranty exposure. Fleet management predictability. None of those motivations have anything to do with how much you want that truck to pull, accelerate, or respond when you need it.
Custom tuning changes that. Not by pushing your engine past its limits — but by letting it operate closer to the limits Cummins already designed in. It’s the difference between a truck that does the job and a truck that does the job well. Better throttle response, real-world power gains, improved highway speed limiters, and in the case of RVs and HD applications, the difference between white-knuckling an uphill grade and actually driving the thing.
This guide covers everything you need to make an informed decision: which platform is right for your application, what each tuning package includes, what hardware you’ll need, and what to expect when you order from Hardway Performance.
These engines are built to run up to their full potential. We simply allow them to do that — while adding pedal response, available engine speed, and highway speed limiters where applicable. Think of it as taking the restrictor plate out.
— Ryan Milliken, Hardway PerformanceReal Numbers
On Real Trucks
All SOTF numbers pulled from our in-house Dynojet 224XLC2. HD figures pulled directly from the ECM. Every number here is from a real truck.
2019–2024 6.7 Cummins
Tested on Dynojet 224XLC2 · 4th gear · torque converter locked · SAE correction factor
| Level | HP | TQ | Gain |
|---|---|---|---|
| Stock | 366 | 876 | baseline |
| SOTF0 | 365 | 875 | stock setting |
| SOTF1 | 394 | 861 | +28HP / −15TQ |
| SOTF2 | 434 | 897 | +68HP / +21TQ |
| SOTF3 | 458 | 978 | +92HP / +102TQ |
| SOTF4 | 481 | 1061 | +115HP / +185TQ |
| SOTF5 | 497 | 1139 | +131HP / +263TQ |
| Level | HP | TQ | Gain |
|---|---|---|---|
| Stock | 399 | 1017 | baseline |
| SOTF1 | 465 | 1029 | +66HP / +12TQ |
| SOTF2 | 469 | 1062 | +70HP / +45TQ |
| SOTF3 | 485 | 1119 | +86HP / +102TQ |
| SOTF4 | 504 | 1165 | +105HP / +148TQ |
| SOTF5 | 526 | 1261 | +127HP / +244TQ |
2013–2018 6.7 Cummins
Tested on Dynojet 224XLC2 · All pulls in 4th gear · TC locked · SAE correction factor
| Level | HP | TQ | Gain |
|---|---|---|---|
| SOTF0 | 350 | 785 | stock |
| SOTF1 | 402 | 874 | +52HP / +89TQ |
| SOTF2 | 421 | 940 | +71HP / +155TQ |
| SOTF3 | 441 | 1016 | +91HP / +231TQ |
| SOTF4 | 457 | 1083 | +107HP / +298TQ |
| SOTF5 | 476 | 1105 | +126HP / +320TQ |
2003–2007 5.9 Cummins
Three custom power levels included — calibrated to your specific build. Switch between levels via laptop reflash.
2006–2007 5.9 Cummins CM849
Five CSP levels — one calibration. Gains based on 100% stock application. Your actual numbers vary based on injectors, pump, turbo, and rail sensor.
Cummins HD — RV, Class 8, Marine
Before and after figures pulled directly from the ECM on actual customer vehicles tuned by Ryan Milliken.
1,150tq
1,225tq
700tq
850tq
1,150tq
1,250tq
HPTuners
vs EFILive
The platform isn’t a brand preference — it’s dictated by your truck’s ECM. Here’s what goes with what.
Verify your vehicle’s HPTuners compatibility at hptuners.com.
Find
Your Tune
| Application | ECM / Platform | Tune System | Positions | Starting Price | |
|---|---|---|---|---|---|
| 2019–2024 Ram 6.7 Cummins | CM2350 / CM2450 · HPTuners | SOTF Shift-on-the-Fly | SOTF0–SOTF5 | $500 | Shop → |
| 2013–2018 Ram 6.7 Cummins | CM2350 · HPTuners | SOTF Shift-on-the-Fly | SOTF0–SOTF5 | $500 | Shop → |
| 2003–2007 Ram 5.9 Cummins | CM849 · HPTuners | TOW / STREET / LEMONS | 3 map stages | $500 | Shop → |
| 2006–2007 5.9 Cummins CM849 | CM849 · EFILive | CSP Custom OS | CSP1–CSP5 | $500 | Shop → |
| HD Cummins — RV / Super C | CM2XXX series · EFILive HD | Full Flash Custom | Full ECM write | $750 | Shop → |
| Class 8 / Dump Truck / Semi | CM871 / CM2350A / CM2880 · EFILive HD | Full Flash Custom | Full ECM write | $750 | Shop → |
| Marine Cummins (2001+) | CM2XXX series · EFILive HD | Full Flash Custom | Full ECM write | $750 | Shop → |
All tunes are 100% emissions-intact and 49-state legal. Hardway Performance does not offer delete tuning.
What You
Actually Need
The hardware requirements differ between platforms. Here’s exactly what to order so you’re not chasing parts after the tune file is ready.
For HPTuners (Light Duty · Ram Trucks)
For EFILive (CM849 + HD Applications)
Running Higher Boost?
If your build is pushing past the stock MAP sensor ceiling, you’ll need a 10 BAR sensor before your tune can read accurately above 50 PSIA. The HW10B is a direct plug-in replacement — billet aluminum, RIFE transducer, complete EFILive scaling table included.
HW10B Install & EFILive Scaling Guide →Skip the Swap.
Send In Your ECM.
Until recently, getting SOTF tuning on a 2022–2024 Ram meant sourcing a completely different ECM. HP Tuners just changed that. Here are your two options — and which one we recommend.
This is a significant cost reduction compared to sourcing a pre-2022 ECM and the path we recommend for the vast majority of 2022–2024 owners. No IMMO relearn, no crank relearn required — as long as the ECM returns to the same vehicle it came from.
We’re continuing to offer this option for customers who prefer it or who need to avoid the HP Tuners turnaround time — but for most people, the upgrade service is the better call.
Both routes are fully compatible with SOTF0–SOTF5 tuning. Not sure which is right for you? Call us at 855-910-3823.
How It
Actually Works
Ordering Your Tune
The process is simpler than most people expect. When you place a tuning order, you’ll fill out your model year, engine, and ECM type directly in the product form — along with any special requests (increased speed limiters, specific power targets, towing vs. performance bias). That information goes straight to Ryan.
For HPTuners SOTF packages, you’ll receive tune files loaded via your MPVI interface. For EFILive packages, files are delivered to your AutoCal or FlashScan device. HD applications require you to ship your device in — or we can include the hardware with your order so everything arrives ready to go.
Current turnaround is 5–10 business days. If your situation is time-sensitive, call us at 855-910-3823 before ordering.
Emissions Compliance — The Short Version
Hardway Performance tunes are written entirely within the factory emissions architecture. We do not offer delete tuning, we do not tune around DPF, DEF, or EGR systems, and we do not remove or alter any emissions-related hardware in the calibration. Every tune we write passes federal emissions standards.
That’s not a legal hedge — it’s how we’ve always operated. The power gains you see above come entirely from unlocking factory-rated headroom that OEM manufacturers left on the table. There’s plenty of it.
Who Writes the Tunes
Ryan Milliken is the founder of Hardway Performance and the calibrator behind every tune file that leaves this shop. His background includes award-winning competitive diesel performance development and thousands of hours on a Dynojet 224XLC2 in-house dynamometer. The calibrations aren’t sourced, farmed out, or modified from base templates — they’re written from scratch for your truck.
If you’ve seen the YouTube content, you already know the level of obsessive detail that goes into this work. The tuning files are the same.
We don’t do copy-paste calibrations. Every file is built for the application in front of us — your engine, your mods, your use case. Generic tunes exist for a reason. This isn’t that.
— Ryan Milliken11 Questions.
One Video.
We put together a straight-answer video covering the 11 most commonly asked questions about Cummins tuning — platform choices, hardware requirements, emissions compliance, the 2022–2024 ECM situation, and more. If you’re not sure where to start, this is 20 minutes well spent.
- → HPTuners vs EFILive — which platform is dictated by your ECM and why you don’t get to choose
- → SOTF hardware requirements — MPVI3/4, credits, SGW bypass cable, and what you actually need to order
- → The 2022–2024 CM2450B ECM situation — the HP Tuners send-in upgrade vs. sourcing a replacement
- → Emissions compliance — what “emissions-intact” actually means and what we don’t touch
- → Turnaround time, process, and what to expect after you order
FAQ
Hardway can also source a compatible pre-2022 ECM for those who prefer that route or need to avoid the HP Tuners send-in timeline. Give us a call at 855-910-3823 and we’ll point you in the right direction.
Stop Leaving
Power
On the Table
Every Cummins we tune has more in it than the factory let out. Pick your application below and let’s put that power to work — with a 5–10 business day turnaround and 100% emissions-compliant calibrations written by Ryan Milliken.
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