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Cummins Versus Duramax: The Best Diesel Engine in 2022

If you find yourself in the market for a diesel engine, you’ll want to know your options. This can be tricky, especially if you haven’t had much experience with diesel engines.

In this article, we’ll look at the two most popular models to see if there’s one that could be considered the best diesel engine of 2022.

Let’s learn more about Cummins and Duramax.

About the Cummins Engine

The first engine under review is the Cummins engine. With over one hundred years of experience in this field, Cummins has a history of building reliable engines. Cummins has three different diesel RV engine models: the X15, X12, and L9. The pulling power of these engines ranges from 300 to 605 hp. 

The X15 is a heavy-duty engine and a great choice for pulling motorhomes. Due to its extra power, some consider it the most popular diesel engine for North American buyers. The X12 is the lightest diesel engine Cummins makes. Yet, its carrying capacity is the highest in power-to-weight ratio. It’s the go-to engine for luxury RVs as it can comfortably tow larger cars or boats behind the motorhome. 

The L9 has been an efficient engine in the Cummins line for over 30 years. It’s a quiet, long-lasting option that provides years of reliable power. Due to its longer life, it tends to have a higher resale value than the other models in this line. 

Close up of car engine
A diesel engine offers better gas mileage than gas engines.

About the Duramax Engine

You have a few models of the Duramax Turbo-Diesel engines to choose from. Developed and used primarily in Chevrolet vehicles, these engines are fuel-efficient, powerful, and capable. They offer a smooth, quiet travel experience and provide the standards of comfort that Chevrolet promotes. 

Duramax Turbo-Diesel engines are measured in liter capacity and come in three sizes: 2.8L, 3.0L, and 6.6L. The 2.8L engine comes with a 5 year/60,000-mile warranty and is a dependable option for smaller vehicles. 

The 3.0L engine claims the best fuel efficiency of all the Duramax engines and works great for medium to large vehicles. Its efficiency allows for a 5 year/100,000-mile warranty. The 6.6L model works best for vans and RVs. Its pulling power is optimized for the weight of trailers or other vehicles attached to a larger vehicle. It also comes with a 5 year/100,000-mile warranty.

Interior of car engine
If you’re on the hunt for a diesel engine, both Cummins and Duramax offer great options.

What Is the Difference Between a Cummins and Duramax Engine? 

Cummins and Duramax engines are similar in many ways. Each line has a variety of models to choose from, depending on your needs. Both produce powerful engines famous for their pulling power, efficiency, and output. 

However, one major difference seems to bring Cummins engines to the forefront, especially in terms of their pulling power and reliability for RV owners. Cummins engines work with larger vehicles. Duramax only produces one recommended for trailers or motorhomes, the 6.6L diesel engine. In contrast, Cummins provides an entire line dedicated solely to RVs. 

Pro Tip: Protect your diesel engine by learning Should You Warm Up Your Engine Before Driving?

What Pulls Better, Cummins or Duramax?

For many vehicles, pulling power is measured in horsepower and torque, or the amount of force an engine can withstand. Though both are important, torque determines pulling power. 

Let’s look at a few numbers to get a better idea of what we’re working with. Cummins engines have won in torque but lose to Duramax in horsepower. The 6.6L engine from Duramax produced 910 lb-ft of torque when used within a 2018 GMC Sierra HD. 

A Cummins engine of similar size produced 930 lb-ft when used within a 2018 Ram Heavy Duty truck. However, when two engines of similar size were compared solely on horsepower, the Duramax engine boasted a horsepower of 450 in comparison to the Cummins’ 400. 

Mechanic repairing engine.
Keep in mind diesel engines come with higher gas prices.

Is Cummins the Best Diesel Engine?

As we’ve seen, Cummins engines have a lot to offer. With their line specifically designed for RVs, Cummins may be the best choice of diesel engines for campers and motorhomes. Additionally, the torque available to the user is an attractive draw. 

However, Duramax engines are also reliable choices for everyday pulling and towing, and the 6.6L engine offers power for trailers and larger trucks. Because of this, it’s difficult to name one engine as better than the other. Each has a specific vehicle and job in mind.  

Which Diesel Engine Is the Most Reliable? 

It’s difficult to narrow down which diesel engine is the most reliable. Both Duramax and Cummins engines boast models that rank high on pulling power, reliability, and overall performance. It comes down to finding the right one for your specific needs.

A Cummins engine may shine in one scenario but may pale compared to a Duramax engine in another. Taking the time to assess your needs and the available options will aid you in finding the perfect one for you. 

Pro Tip: Are you wondering Why Is Diesel More Expensive Than Gas? We took a closer look to uncover the truth!

Is Owning a Diesel Worth It?

Diesel engines can serve as a great asset. They offer better gas mileage than gas engines, and their pulling capacity is higher than that of a standard one. Due to their lack of spark plugs and distributors, diesel engines tend to call for fewer trips to the mechanic. 

You may find great value in owning a diesel engine, but it may not be for everyone. While you may get better gas mileage, a diesel also comes with higher gas prices. They also tend to be louder than standard engines and emit more emissions on average. 

Like choosing between Cummins and Duramax, deciding to switch from a standard to a diesel engine is all based on what you need. The good news is, no matter the job at hand, you’re never short of reliable and efficient options. 

Do you have a diesel engine? Tell us your experience in the comments!

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