best 6.7 cummins upgrades

Best 6.7 Cummins Upgrades That Won’t Void Warranty

Today, we’ll go over some of the best 6.7 Cummins upgrades as well as suggestions for handling warranty claim denials. The 6.7 Cummins engine is one of the most well-known pickup truck engines.

Dodge developed the Cummins and outfits several of its pickup trucks with the tried and true diesel-powered motor. While these engines produce significant power, you can modify and tune them to get even more out of them.

However, if you own a new Cummins, you need to know which mods affect your truck’s factory warranty because you will likely want to delay them until after the first three years or 36,000 miles. Do not worry, though. There are plenty of modifications you can do as soon as you drive your new truck off the lot.

History of the Cummins Diesel Engine

Cummins is an international manufacturer of engines for cars, aerospace, motorhomes, RVs, buses, and heavy-duty commercial vehicles. The company also builds equipment for drilling, gas compression, construction, and defense, and it has a history that spans more than 100 years.

By the time Dodge teamed up with Cummins, the latter already had a name in the automotive industry, so enthusiasts were thrilled to learn that Dodge would add the first-ever 6.7-liter Cummins Turbo-Charged Diesel engine in 1989.

Dodge Cummins Diesel trucks have been powering Ram 2500, 3500, and 4500 for more than 30 years. However, the 6.7-liter Cummins is the newest version of the best-selling motor. It was introduced to the line in 2011.

With the 6.7-liter engine, the RAM 3500 was the first truck in its class to get more than 1000 lb-ft of torque. Other automakers responded, starting a new era of trucks with 1,000+ lb-ft of torque. The 2021 RAM 3500 with a 6.7-liter Cummins engine is comparable to the  2021 Ford F-450 SuperDuty, with the new Ford producing slightly more horsepower and torque but carrying a much heftier price tag.

Cummins 6.7 Engine

What Voids the 6.7-liter Cummins Warranty?

The warranty covering new RAM trucks is pretty clear about what voids the contract, and you may be surprised to learn that many of the upgrades you might think you need to put off until after the warranty expires are allowed by the manufacturer. However, there are some stipulations.

Here are the actions that void your Cummins diesel truck’s warranty:

  • Altering or tampering with the speedometer
  • Adding a device that changes the speedometer

Other upgrades will not void your warranty. However, the dealership may deny a warranty claim if the parts you add cause other components to fail. The pieces you switch out are no longer covered because the warranty only covers parts installed through the dealership or during manufacturing.

Your warranty also fails to cover your paint or rust damage if you repaint your truck or add an anti-rust product. You also need to maintain your vehicle because any damage caused by failing to perform routine maintenance is not covered.

Tuners also void your warranty, and because most aftermarket mods require tuning, it is better to go with Mopar parts that you can use without a tuner.

Cummins Warranty Timeframes

The warranty for most parts and systems on your Cummins-powered truck is limited. So, here is a quick guide to help you determine which components are still covered under your vehicle warranty:

Limited Bumper-to-Bumper Warranty

Your entire RAM truck, except wearable components, like windshield wiper blades, batteries, filters, light bulbs, fuses, and tires, has coverage for the first three years or 36,000 miles.

Cummins Diesel Warranty

Cummins diesel engines have a longer warranty than most gasoline-powered trucks at five years or 100,00 miles.

Emissions Warranty

The emissions warranty is lifelong on Cummins diesel motors. However, altering it will void the lifetime coverage.

6.7-liter Cummins Performance Mods

When you purchase your RAM truck, it is understandable that you want to modify it. However, Cummins finely tunes the 6.7-liter engine, which is one reason it produces such impressive numbers.

If the countless hours Cummins skilled engineers spent crafting the 6.7-liter motor, there are some performance mods you can do. There are also some you might want to put off until you’ve put some miles on your truck.

Cold Air Intake

Cummins diesel engines come with a relatively advanced cold air intake (CAI) system. Replacing it with an aftermarket kit will not necessarily help your vehicle gain horsepower. However, it is an ‘upgrade’ you can do without voiding the warranty.

High-quality aftermarket S & B air intakes are available for less than $500. It is a good idea to have the dealership install it, and you can also talk to the parts department about what other options they may have available.

While adding a performance CAI will not make a significant impact on the overall performance, if any. It may alter your engine’s sound and may extend your motor’s life if it does a better job of keeping your engine cool.

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Cummins diesel engines all come with turbochargers. However, you can upgrade the turbocharger to get even better gas mileage, torque, and horsepower. An Aura Twin-Turbo Kit is a good choice for around $5,000, depending on the year and model.

Nitrous Oxide Injectors

Nitrous oxide injectors are excellent upgrades for diesel-powered motors. While NOS boosts any engine with an increase of oxygen, adding it to a gasoline engine can prove problematic if the air to fuel ratio is off. Cummins engines have more flexibility, though, and you can gain a short boost of several hundred horsepowers and lb-ft of torque.


Exhaust is something that a lot of truck owners have near the top of their mod list. Some dealerships may tell you an exhaust system will void your warranty. The warranty guide does not mention the exhaust system at all. However, a technician may find that the exhaust alteration caused another engine failure, thus voiding the affected components’ warranty.

To avoid coverage issues, you can opt for an inexpensive DPF-back system, like the 5″ aluminized exhaust from Diamond Eye for less than $300 or another DPF-back option.


An intercooler is an excellent mod for vehicles with superchargers or turbochargers because it cools the air these systems pull into the engine. An intercooler will not necessarily void your warranty. However, there is always a possibility that the dealership could blame something else on the component.

Oil Filter Bypass Kit

An oil filter bypass kit adds filtration for the oil in your engine, which helps extend your engine’s life and keep it running efficiently. Amsoil is a trusted brand that sells a kit for 2004 and later Cummins diesel engines for $392.45.

Adding this mod should not void your warranty as it is not altering the vehicle’s output or altering the computer codes or odometer. The only way the bypass filter could affect the coverage is if a part broke off the bypass and clogged the engine, which is highly unlikely, especially if you have it professionally installed.

Lift and Leveling Kits

If you want more ground clearance, you will likely want a suspension or body lift. You should be able to install either on your vehicle without it affecting your warranty plan. However, raising your truck more than two to three inches will likely cause the dealership to deny claims.

Many dealerships install lifts. So, if this is a mod you want, have the dealership you take your truck to for service do the work and use approved parts.

This might interest you: Best Clutch Kits for Cummins

Wheels and Tires

Upgrading your rims and tires is one of the safest modifications you can do. However, like most components and systems, there are limits. Some dealerships deny warranty claims if you add tires that are above a specific size. Nevertheless, if you go to an approved RAM service center, you should not have any problems later down the line.

Cummins 6.7 Upgrades


Searching for information on the Cummins engine returns many results, yet much of the data is inconsistent and challenging to piece together. So, we addressed some of the most commonly asked questions here.

Question: Is the Dodge 6.7 Cummins a Good Engine?

Answer: The 6.7-liter Cummins replaced the smaller 5.9-liter, and it is a cleaner-burning, more efficient motor. Dodge adopted the change in 2011 and added a diesel particulate filter (DPF) to keep the engine free from the debris that would otherwise accumulate and potentially clog vital parts. That helps to increase the lifespan of your motor.

Question: Does DPF Delete Void Cummins Warranty?

Answer: Although DPF helps to keep contaminants out of your diesel motor, it can also reduce the horsepower your truck receives. So, many RAM owners install a DPF delete. The delete does not void the warranty. However, it requires a tune that alters fuel consumption, which is illegal and can void the manufacturer’s warranty.

Question: Does DPF-Back Exhaust Void Warranty?

Answer: According to the warranty, no parts or components, even those not produced by Chrysler, void it. However, some features may lead to more claims denials. DPF-back exhaust is not one of those components, making it one of the safest mods to purchase.

Question: Does a Diesel Tuner Void the Warranty?

Answer: Yes, a diesel tuner will void your 6.7-liter Cummins warranty, making it impossible to use nearly every mod efficiently. Many components require a tuner to work at all and certainly to produce noticeable results. However, you can add some upgrades early on and tune your truck after being in service for a few years to get the most out of your investment.

Final Advice on 6.7-liter Cummins Mods

Modifying your vehicle always comes with some risk of warranty denials. If you damage a component during the installation or a component you upgrade causes damage to another part down the line, RAM will deny your claim. However, the vehicle warranty is pretty specific about the two things that void the contract, tampering or disconnecting the odometer.

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Other than that, it is unlikely that the manufacturer will void your coverage, but getting claims approved with extensive engine modifications could prove troublesome.

If you are in the market for a truck and looking for information because you intend to do upgrades shortly after you buy, you might want to spend the money on factory upgrades instead. RAM offers various performance enhancement options that will give you real benefits without causing you stress over your warranty.

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