6.7 Cummins MPG After EGR DPF Delete | Fuel Economy Results

Your truck guzzles fuel. Regens waste diesel. When you delete the emissions system on your truck with a 6.7 Cummins, it can bring fuel savings and MPG jumps.

However, real gains from a 6.7 Cummins delete stay modest. Owners see 1.5-5 MPG better, often 2-4 MPG. It depends on your tune, driving, and truck year. Highway can hit 20-25 MPG deleted.

Many owners ask if deletes brings huge savings. I talk to dozens. I read forums. The truth sits in the middle. Deletes help, but not magic. Read on. I share real deleted 6.7 Cummins fuel mileage real data and explain the factors that affect your fuel mileage gains.

From highway driving to towing, we break down what you can realistically expect. Additionally, we will discuss how tuning, driving habits, and modifications influence the 6.7 Cummins mileage after EGR DPF delete.

Real-World 6.7 Cummins Mileage Improvements after Delete

Claims promise 10 MPG gains. Real life disappoints many. Modest bumps happen with the right setup.

Typical 6.7 Cummins delete gives 1.5 - 5 MPG increased gas mileage. I follow Cummins groups online. Owners share scans and logs. The data shows patterns. Early trucks (2007-2012) gained more. Later ones less.

• Pre-delete baseline: Stock trucks typically achieve 13.9–19.8 MPG.
• Post-delete results: Highway reaches 17.6–27 MPG in gentle driving, while mixed/in-town driving sees 18–22 MPG. Towing reduces MPG significantly, often to 12-15 MPG.

Examples from Owners

• A 2012 model originally achieved between 12 and 14 mpg (stock) has been reported as achieving 16-25 mpg (deleted).
• There was an increase from 19-21 mpg (stock) to 22 mpg highway for a 2017 truck after being deleted.
• A 2020 truck owner reported that he achieved approximately 28 mpg on a long trip with gentle driving.

The averages stay lower. Most consistent reports: 2-4 MPG up. Some say no gain. Bad tunes hurt. Aggressive driving wastes fuel.

Why Gains Stay Modest

Emissions rob some power. Regens burn fuel. EGR adds soot.

Industry professionals indicate that there are several diesel engineers who have tuned newer emissions-compliant vehicles to achieve the same or nearly the same mpg as a deleted truck.

Experts note: Properly tuned emissions on trucks match deleted mileage. Deletes shine in reliability, not always MPG.

I tested a buddy's deleted 2018. We drove the same route. His got 21. My stock got 19.5. Nice, but not life-changing.

Towing data: Stock 10-13. Deleted 12-15. Still drops hard.

Factors That Affect Gains

Tuning, tire size, driving habits, and year of truck are just some examples of what affect the mpg results, as there is no absolute way to determine mpg potential on deleted trucks without removing restrictions and optimizing diesel fuel flow.

Factor	Impact on MPG
Tune Type	Eco tune gives the best MPG; performance tunes give the worst MPG
Driving Style	Gentle driving: +3–5 MPG; aggressive driving: ~0 MPG gain
Truck Year	Older trucks usually see larger MPG gains
Tires / Load	Larger tires and heavier loads reduce MPG

Drive easily for the best results. Keep speeds 65-70. Avoid jackrabbit starts. In my experience, deletes help most off-road or heavy use. Daily drivers see smaller wins.

Tuning Matters for 6.7 Cummins Fuel Economy Gains

If you are looking to improve 6.7 Cummins MPG after deleting the DPF and EGR, it is important to properly tune the engine for optimal performance. The type of tune you choose can greatly affect deleted 6.7 Cummins fuel mileage.

Bad tune wastes money. Good one unlocks savings. Choice changes everything.

The most common type of tuning done is Stock/Eco tunes, which typically add anywhere from 2-4 mpg over stock tunes, making them ideal for most daily drivers and long highway trips.

Performance tunes, on the other hand, not only add power, torque, and performance, but aggressive driving of your truck with performance tunes can lower the MPG and may even result in lower MPG's than the stock settings while driving around town.

Shift-on-Fly options allow you to easily switch between Eco and Performance tunes. An Eco-tuned engine gives you the best overall mileage for daily driving, while a Performance-tuned engine maximizes the amount of power at your disposal when necessary.

Without proper tuning, a delete can cause high exhaust gas temperatures or injector issues. Gentle driving combined with an eco-focused tune usually provides the best 6.7 Cummins delete MPG results.

I learned this hard. A friend deleted his truck. He picked a hot tune. Mileage dropped below the stock in the city.

Tunes rewrite the ECU. They control fuel, timing, and boost.

Tune Types Compared

Tune Type	MPG Impact	Power Gain	Best For
Stock / Eco	+2–4 MPG	Mild	Daily driving, highway cruising
Performance	-1 to +1 MPG	High	Towing, spirited driving, fun
Switchable	Best of both	Varies by mode	Drivers who want versatility

I suggest known tuners like H&S Mini Max V1/V2. Read reviews. Custom tunes beat off-the-shelf.

One owner shared: Eco tune got him 24 miles highway. Switched performance: 18 miles. In my circle, most are happy with eco or switchable.

Horsepower and Performance Gains after 6.7 Cummins Delete

When emissions systems are deleted, the 6.7 Cummins engine operates more efficiently because removing them reduces backpressure in the exhaust system.

Many owners report horsepower gains of 15–20%, or 30–100 HP, depending on the quality of the delete kit and tuning setup. Typical 50-75 with a good tune.

With some setups, users report an increase of 75-150+ horsepower.

Increased performance is due to:

• Unrestricted exhaust flow, reducing backpressure.
• Optimized operation of the turbo without oil contamination from the crankcase venting system.
• Improved air-to-fuel mixture leading to enhanced efficiency of combustion.

When these factors are combined with a properly tuned engine, the overall fuel economy of a deleted 6.7 Cummins increases, as well as achieving better acceleration and towing capability.

I know a guy. Deleted for towing power. Gained 80 HP. Pulls hills easily now. Shops dyno 100+ gains. But power tempts a heavy foot. Hurts MPG.

HP Gains Table

Setup	HP Gain	Torque Gain
Delete only	15–30 HP	50–100 lb-ft
Delete + Mild Tune	50–75 HP	100–150 lb-ft
Delete + Aggressive Tune	100+ HP	200+ lb-ft

Reliability improves, too. Less soot.

My take: Power big pro. But control it for mileage.

Cost Analysis: 6.7 Cummins Delete Kit vs. Long-Term Fuel Savings

Installing a 6.7 Cummins delete kit requires an upfront investment but can provide modest fuel savings over time.

Delete kits run $800-2000+. Total with tune/labor $2000-5000. Savings pay back over miles.

Aspect	Details
Delete Kit Cost	$800–$2,000 (parts, labor, and tuning)
DPF Replacement (if needed)	$2,000–$8,000
SCR Catalyst Replacement	$8,000–$12,000
Estimated Maintenance Savings	$3,000–$5,000 over truck lifespan by avoiding DPF/EGR issues
Fuel Savings	2–4 MPG improvement at $3/gallon, break-even at ~36,000 miles for a $2,300 delete

Fuel mileage gains are real for deleted 6.7 Cummins diesels, but they are minimal. Any cost associated with the kit, tuning, and ongoing maintenance must be weighed against your long-term savings in fuel. Therefore, proper planning ensures the delete investment pays off while improving performance and efficiency.

I crunched numbers for my truck. Fuel $4 a gallon then.

Cost Breakdown

Item	Cost Range
Delete Kit	$800–$2,000
Tuner / Tune	$500–$1,500
Labor (if not DIY)	$500–$1,500
Total	$2,000–$5,000

Stock repairs are expensive.

Potential Stock Repair	Cost
DPF Replacement	$2,000 – $5,000
EGR Cooler	$1,000 – $2,000
SCR / DEF Issues	$2,000+

Deletes save $3000-6000 lifetime on parts.

Fuel savings: 3 MPG gain, 20,000 miles/year = 300 gallons saved. At $4 = $1200/year.

Payback 2-4 years. I drive 15,000 miles. Slower payback.

But no regens, no limp mode. Peace is worth it for some owners.

6.7 Cummins 4"DPF Delete EGR Delete Kit for 2010-2014 Ram

$272.77

Buy Now

Downsides of Deleting 6.7 Cummins for MPG Improvement

While deleting a 6.7L Cummins is supposed to increase MPG and performance, there are serious drawbacks to take into consideration.

Deletes illegal on-road. Fines high. Warranty gone. Resale hurts.

1. Legal issues: Removing emissions equipment could be illegal under both Federal and State laws and can result in fines or failing an emissions inspection.
2. Environmental impact: Deletes can increase emissions, which contribute to air pollution.
3. Failing emissions inspection: Failed emissions tests can create problems regarding vehicle registration.
4. Voids warranty: DPF/EGR removal will void a manufacturer's warranty.
5. Resale Issues: Trucks that have deletions will deter prospective buyers and affect resale value.

Some regret. Caught, big bills. I chose stock. Reliable, legal. But off-road users love it. Weigh risks.

Being familiar with these cons should give a good basis for making an informed decision when thinking about the deleted 6.7 Cummins MPG upgrade.

Improve 6.7 Cummins Fuel Efficiency with Modifications

Besides a delete, several modifications can help improve 6.7 Cummins MPG and overall fuel efficiency:

Cold air intake, better tires, aero tweaks add MPG. Keep stock legal.

• A Cold Air Intake (CAI) allows for increased airflow to the engine, helping it to burn fuel more efficiently.
• Tuners/Programmers allow for optimization of fuel mapping that yields the best mpg possible from a 6.7 Cummins mileage after EGR DPF delete.
• A High-Flow Exhaust System allows for less backpressure and therefore increases engine efficiency.
• Adding Boost Tubes allows for improved turbo efficiency and a smoother delivery of power.
• By using Lift Pumps (FASS), you can ensure a continuous supply of fuel to the engine, providing improved mpg.
• Upgrading your tires with lighter or more efficient options reduces rolling resistance.
• Turbocharger Upgrades allow for improved flow of air through the turbo system and improved ability to control boost, which leads to increased fuel economy.
• Injector shave seen some major evolution, and today's injectors atomize fuel and create better combustion.
• Finally, aerodynamic modifications to the vehicle reduce drag, which results in better highway MPG.

When you couple all these upgrades with proper tuning and gentle driving habits, you can achieve the maximum potential of performance and mpg of the 6.7 Cummins.

I tried non-delete mods. Gained 2 MPG.

Mod Impact Table

Mod	MPG Gain	Cost
Cold Air Intake (CAI)	0.5 – 1 MPG	$300 – $500
Low Rolling Resistance Tires	1 – 2 MPG	$800+
Aerodynamic Mods	1 – 2 MPG (highway)	$200 – $1,000
Programmer / Tuner	1 – 3 MPG	$500

Combine for 3-5 MPG. I added CAI and cover. Got 19-20 highway. Easy, legal.

What Does a 6.7 Cummins Delete Actually Mean?

Emissions parts choke your engine. Deletes remove them. You breathe easier. But risks come too.

A 6.7 Cummins delete removes DPF, EGR, and SCR systems. Real gains hit 2-4 MPG with good tunes. Some see more on highway drives.

I own a 2015 Ram 3500 with the 6.7 Cummins. I thought about deleting for years. Friends told stories of huge gains. I wanted better mileage for long hauls.

A delete means removing key emission parts. The DPF catches soot. It clogs over time. The engine burns extra fuel in regens to clean it. EGR sends exhaust back to the intake. It cools combustion but adds carbon buildup. SCR uses DEF fluid to cut NOx.

Owners remove these for freer flow. I looked at kits. They include pipes, blocks, and tuners.

Real MPG Before and After

Stock trucks vary a lot. Older ones get lower numbers. Newer ones do better with factory tunes.

Driving Type	Stock MPG Range	Deleted MPG Range	Typical Gain
Highway	16–20 MPG	19–25 MPG	2–5 MPG
Mixed / City	14–18 MPG	17–22 MPG	2–4 MPG
Towing	10–14 MPG	12–16 MPG	1–3 MPG

Data comes from forums like CumminsForum and Reddit. Many report 2-3 MPG jumps. One guy with a 2012 went from 14 highway stock to 20 deleted. Another 2017 saw 19 to 22.

But not all win big. Newer trucks (2013+) have better stock systems. Gains shrink to 1-2 MPG. Some experts say tuned stock trucks match deleted ones.

I drove stock for 100,000 miles. I got 17-18 highway empty. Towing dropped to 12. After thinking hard, I kept it stocked for now. But I see why others delete.

Towing hurts mileage the most. Deleted trucks still drop to 12-15 MPG heavy. Gentle driving helps most.

Tip: Track your own numbers. Use hand calculations. Truck gauges lie high.

FAQs

Does DPF delete increase MPG?

Yes. A DPF delete can improve 6.7 Cummins fuel mileage, typically adding 1.5–5 MPG depending on tuning and driving style.

Does EGR delete increase MPG?

Yes. Removing the EGR reduces exhaust restriction and improves combustion efficiency, slightly boosting MPG. Helps with good tune. 1-2 MPG.

How long do delete kits last?

With proper installation and maintenance, delete kits can last the life of the truck. Steel pipes endure.

Will a delete improve engine longevity?

Yes, if properly tuned. Less soot, cooler runs. It reduces DPF/EGR-related failures but requires careful maintenance.

Will a delete improve my towing performance?

Yes. Less backpressure improves turbo efficiency, giving better power and torque while towing. Less regen interrupt.

How many miles will a deleted 6.7 Cummins last?

A well-maintained, deleted truck can easily exceed 300,000–400,000 miles. 500,000+ with care. Many hit million.

What's the difference between DPF delete and EGR delete?

DPF delete removes the diesel particulate filter for better exhaust flow. EGR delete disables the exhaust gas recirculation system. Both improve performance, but DPF mainly affects emissions and backpressure, while EGR affects combustion efficiency.

Final Verdict: Is Deleting a 6.7 Cummins Worth it?

Deletes offer modest MPG and big power. But risks high. Weigh for your needs.

If you delete the emissions system on a 6.7 Cummins engine, you can achieve better fuel economy, increased horsepower, and improved towing capacity. Most owners report improved MPG by 2-5 MPG (especially when driving on the highway), and you can expect to increase your horsepower by 15-20%.

However, there are several disadvantages to deleting your 6.7 Cummins emissions system, including potential legal repercussions for having no emissions on your vehicle, voided warranties, and having difficulty passing emissions inspections or selling your truck in a future sale.

To safely take full advantage of the deleted 6.7 Cummins MPG increase, proper tuning and driving habits are crucial. For an owner who wants to achieve better performance, modest fuel savings, and is willing to manage the negatives involved, deleting your 6.7 Cummins emissions system may be the right choice.

An owner who wants to improve fuel performance through efficiency-focused tunes, along with selective modifications, has an excellent alternative and can achieve similar results while also avoiding the additional risks of deleting their 6.7 Cummins emissions system.

About the Author- John Barrett

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