Top Dodge Cummins Years To Avoid and Why

Dodge Cummins engines are typically powerful, and power Dodge trucks to drive across any terrain, but are there Dodge Cummins years to avoid?

Sure, there are some Cummins years you should never buy because they are linked with lots of mechanical problems.

Apparently, the first-gen Cummins are among the worst years to avoid; firstly, because they are too old to be driven in modern times like now, and secondly, they aren’t as reliable as the newer models.

Also, there are other gens of Dodge Cummins years to avoid, which are explained in this article!

Dodge Cummins Years To Avoid

Since 1989, Dodge has kept on using Cummins diesel engines on its heavy-duty trucks. Well, sometimes, the Cummins engine is not used as the standard option; you have to choose it as an optional extra. The Cummins engines are mostly diesel-powered and built for heavy-duty applications.

Cummins engines are available with four or six cylinders; however, they produce a lot of power for towing and hauling heavy payloads.

While the Cummins engines deliver outstanding performance on Dodge Ram trucks, some Cummins engine models designed in specific years are very unreliable.

Hence, it is advisable not to choose these Cummins years for your new Ram truck. If you’ve got a V8 option alongside a Cummins engine produced in these years reviewed below, it would be much better to choose the V8 engine option; you’d be more please in the long run.

See Also: Dodge Ram V6 vs V8 Engines

1. 3.9L Cummins Engines (1989 – 1994)

  • Engine options: 4-cylinder 3.9L diesel, Cummins 4B/4BT/4BTA
  • Horsepower and Torque: 105 or 170 HP and 265 or 400 lb-ft

The major reason to avoid the 1st-gen Cummins engine on Dodge Trucks is that they are really old and highly inefficient compared with the engines available at the moment. These first-gen Cummins engines were available as engine options for the 1989 – 1998 Dodge Ram 250 and 350 pickup trucks.

Well, as expected of an old engine, you can only get a maximum of 160 horsepower from the engine(s). However, the torque output is pretty impressive, up to 400 lb-ft, which was far more than what you’d get from the Ram gasoline engine options at that time.

2. 5.9L First-Gen Cummins Engine (1989 – 1998)

  • Engine options: 6-cylinder 5.9L diesel, Cummins 6B/6BT
  • Horsepower and Torque: 160 HP and 400 lb-ft

The first-gen Cummins had 5.9L diesel engine options produced between 1989 – 1998; these engines were also included as options in most Ram trucks manufactured within the specified years.

Well, the Cummins 5.9L 6B and 6BT engines are too old and unreliable – even though they produce a lot of torque power. Also, the 5.9L Cummins is linked with constant transmission failure.

3. 2007 & 2008 6.7L Dodge Cummins

  • Engine options: 6-cylinder, ISB, B6.7N
  • Horsepower and Torque: 150–400 HP at 2800 rpm and 610–1,000 lb-ft at ~1600 rpm

Although several improvements were seen on the 6.9L Cummins engines, some specific years failed to earn high-reliability scores across websites and platforms. However, you’d get tremendous power for any truck activity you wish to engage with using your Dodge Ram pickup.

Most newer Ram trucks manufactured from 2008 have the Cummins 6.7L diesel engine available as an option. The torque response from this engine is topnotch, but it is listed as among the worst years to avoid because they simply did not score high-reliability scores as other Cummins models.

See Also: Are Dodge Chargers Reliable? (Dodge Charger Reliability)

Related Questions

How Many Generations Are Dodge Cummins Engines?

Currently, Dodge Cummins is in its fifth generation, which started with the 2009 Dodge Cummins models. This latest generation is very much reliable and built to match the sophisticated nature of modern truck engines. Since the first Cummins engine launched in 1984, there have been five generations:

  • 1984 – 1994 First Generation
  • 1995 – 1998 Second Generation
  • 1999 – 2003 Third Generation
  • 2004 – 2008 Fourth Generation
  • 2009 – Present Fifth Generation

What Are The Common Problems With Dodge Cummins Engines?

These worst Dodge Cummins years are linked with transmission failure, gear shifting issues, and turbo failure. Apparently, there are other problems you may face with these Cummins engines, including engine block cracking, but the ones mentioned above are the commonest. Maintaining a Dodge Cummins engine costs between $800 – $1,200 annually.

Are Dodge Cummins Powerful?

As a diesel engine, the Dodge Cummins is usually among the most powerful engines in Dodge Ram engine lineups. The 2020 Dodge Ram (with the Cummins 6.7L engine) ranks as an all-time-best diesel pickup truck. It outputs 400HP and is the first diesel powerplant engine to produce 1,000 lb-ft of torque.

Do Dodge Cummins Last Long?

How long can Cummins engines last? A well-maintained Cummins engine is expected to last anywhere from 300,000 – 350,000 miles.

However, there are many factors that can come in-between and shorten the engine’s lifespan. Also, the dependability of Cummins engines depends on the model you got on your truck.

Which is Better Cummins or Duramax?

Cummins and Duramax are the top two Diesel engine options for pickup trucks. These two engines are incredibly powerful and reliable; however, Duramax engines typically give you more horsepower than Cummins; on the other hand, Cummins engines give you more torque.

That said, choosing between Cummins and Duramax is more like choosing between horsepower gain and torque gain. But then, you won’t find Duramax diesel engine and Cummins diesel engine available as options for the same pickup truck.

Cummins engines are typically used in Dodge Rams, and Duramax engines are used in General Motors vehicles.

See Also: Worst 7.3 Power Stroke Years To Avoid and Why


So, what are the Dodge Cummins years to avoid? This article has clearly listed the specific Cummins engine years and models to be cautious about; the identified years have low reliability ratings and have been linked with regular mechanical problems.

However, this does not dispute the fact that Cummins diesel engines are among the industry’s best options for diesel-powered trucks.

Also, the newer Cummins are incredibly powerful and reliable. If you’re buying a Dodge RAM truck for heavy-duty applications, consider getting the Cummins engine option – you’d love the performance.

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