For more than 30 years, the Cummins engine has been the primary power source of Dodge Ram trucks. They provide anything and everything a heavy-duty vehicle demands. They are long-lasting, durable, strong, and reliable. But there really is no such concept as “absolute good.” There are several theories and discussions when it comes to the topic – “Which Dodge Cummins years to avoid?”
It is vital to pinpoint the optimal years if you really want to invest your hard-earned money in a car fueled by the Dodge Cummins. In this post, we will be looking at some of the features of different generations of Dodge Cummins and discuss why some of the years should be completely avoided.
In short, we advise you to avoid the 2003, 2001, 1999, 1993, 1992, and the 1991 Dodge Cummins models. Compared to the most recent models, these years had the most unfavorable feedback from drivers and the public.
Many challenges have arisen because of these years. Some of the most prevalent include transmission malfunction, charging mechanism difficulties, and electrical problems. These may be expensive to deal with and unpleasant for any driver.
Are Dodge Cummins a Reliable Truck ?
Cummins engines are among the most often used engines in diesel trucks. If you are thinking about buying a brand new or used vehicle with a Cummins unit, you should find out how long the motor is predicted to survive.
Diesel engines are designed to be powerful and efficient. You will be able to pull more while getting excellent fuel efficiency and peace of mind reliability. We will go over the distinctions between the 5.9L and 6.7L versions, as well as why Cummins engines are so popular.
Cummins brand is known for its dependability and long-lasting motors. 5.9-liter motor has a range of 300,000 to 400,000 kilometers, whereas 6.7-liter engine falls somewhere in the center, at 350,000 with no alterations and appropriate maintenance.
Cummins motors are now found in long-haul vehicles, minibuses, pickup trucks, industrial equipment, and farming gear. Not only that, but these engines can power trailers and be utilized in vehicles to tow RVs.
5.9L static turbo lasts a long time since it is restricted to below 45psi but does not require continual high boost fluxes. On the negative, turbo lag may result in decreased RPM. On the other hand, 6.7L has a variable turbo, which makes it more potent and allows it to respond faster at lower speeds.
Brief History of Dodge Cummins
5.9L 12 valve – 1st Generation (1989-1994)
Very first-generation Dodge Cummins was introduced in 1989. One of the greatest things is that they are powered by a 5.9L 12 Valve engine. Horsepower and torque figures are 160 hp and 400 pounds-feet, respectively. They were an enormous success at the time. They were originally utilized for agricultural reasons. The components are gear driven, and there are three transmission options. These engines include two battery versions as well as direct fuel injection.
They range in price from $1500 to $100,000. Despite being less sophisticated than current engines, there are several reasons why you should avoid them.
12V – 2nd Generation (1994-1998)
Following the enormous success of the first-generation engines, the second-generation engines were introduced in 1994. They released fresh designs, a few improvements, and retained the endurance of the first generation.
Horsepower and torque were increased. Horsepower was 175 and the torque was 420 pounds to feet. However, between 1996 and 1998, Cummins manufactured several variants with horsepower up to 215hp.
Furthermore, body layout was drastically altered. There are two modes of transmission (one manual and one automatic). 2nd generation Cummins has the same Inline-6-cylinder engine architecture as the first. Oil consumption is 11 liters, and the controlled speed is up to 2700 RPMs. There are, nevertheless, certain causes why you should ignore them.
24 Valve Cummins – 3rd Generation (1998-2003)
In 1998, the next generation was launched with several improved features. They are identical to the second generation. Talking about the engines, on the other hand, have superior coolant. Average controlled speed is 2700 RPMs, like with the previous version.
However, the torque and horsepower were increased. Also, engine produced 245 horsepower and 505 pounds per foot of torque. They feature a more powerful intercooler. Surprisingly, third generation Cummins also has two gearboxes.
Turbocharger stayed the same as before. There were two engine variants in 2001 and 2002. They produced varied amounts of horsepower and torque. Those versions had 235 and 245 horsepower. Torque, on the other extreme, was 460 and 505 pounds-feet, respectively.
5.9L Cummins – 4th Generation (2003-2008)
Cummins engine expanded on the previous generation’s specs, both in terms of design and engine output. Cleaner-looking trucks replaced rugged-looking vehicles, and engines got more complex and efficient.
Electromechanical rotary pump was replaced by a CP3 fuel injection pump. Before supplying fuel, the CP3 injector applies pressure. Although this pump is more robust and dependable than electric injectors, it falls short of mechanical injection systems. The pressure provided by CP3 prior to fuel delivery makes the motor more economical than the previous generation.
This generation employs two turbochargers. Holset HE341CW blends the advantages of a constant geometry structure and a wastegate layout (mechanically regulated) (introduced in 2003). Also, HE351CW turbocharger featured a constant geometry turbocharger as well, but its wastegate was regulated electrically.
Furthermore, electrical differential in the secondary turbocharger results in fewer emissions and improved performance. Additional turbocharger, the HE351VE, was added in the later years of this series. This redesigned turbocharger decreased truck emissions while also improving durability.
6.7L Cummins – 5th Generation (2019-present)
After 10 years of fourth generation trucks, Ram launched its new 5th Generation Cummins HD trucks in 2019. After driving them, it is evident that the fifth generation Cummins is the most competent and strong Ram pickup to date! Ram 3500s come standard with a 6.7L High-Output Cummins motor combined with an Aisin gearbox, which produces 1,000 lb/ft of torque and 400 hp.
Even the base trucks are outstanding, with the 68RFE automatic gearbox delivering 850 lb/ft of torque and 370 hp. Nevertheless, torque and horsepower are only two components of the ratio, and we have had several enquiries concerning the fifth Generation 6.7L Cummins Turbocharged characteristics.
The Best Dodge Cummins Years to Buy
If you want the finest Dodge Cummins, we recommend the 4th and 5th generation. They have been modernized, have the most recent technology, and provide us greater services.
Significant benefits of the 4th generation Cummins
This generation brought with it everything unexpected. They had a fresh look, layout, stability, interior, and engine power. They significantly increased their horsepower and torque. Although it differed from year to year. The maximum hp is 350! Are you concerned about the lowest?
Even the smallest was 305 horsepower. The torque power spectrum begins at 550 and finishes at 650 pounds per foot. They have controlled speeds ranging from 3000 to 3500 RPM. They also had a large engine oil capacity of 11.4 liters.
Consider the transmission. They have two transmitters in later years and three in previous years. Not only that, but they also feature a larger intercooler with a capacity of 32 qt.
Significant benefits of the 5th generation Cummins
Recently launched most prominent version had great horsepower, numerous advancements, and magnificent styling. This generation is separated into two sub generations: the early years and the latter years. They do, however, have tremendous power.
Their horsepower ranges between 350 to 400. They also have a lot of torque. Motor scale runs from 850 to 1000. They also have a redesigned four-door cab style. They provided a three-pedal manual gearbox from 2011 to 2019. Electronic Stability Control is available on the 2500 and 3500 models.
Air suspension was available in both the 3500 and 2500 models in 2014. Keyless start was also offered. Additional features have been improved throughout the years and does not seem to provide less than the previous generations.
The Worst Dodge Cummins Years to Avoid
 1991, 1992, and 1993 Dodge Cummins years (1st Generation):
All these years fall in the category of the 1st generation Cummins and there are a lot of reasons why you should avoid them and why these were placed at the number one spot in our ‘Dodge Cummins years to avoid’ list.
- They are extremely old.
- When compared to contemporary engines, the power and torque are much lower.
- Few of them that are now accessible are rusty and crude.
- Many of them had transmission problems.
 1999, 2001, and 2003 Dodge Cummins years (3rd Generation):
Third generation of the Dodge Cummins indeed had their own set of add benefits when compared to the second. But, if you compare the more recent ones to the 3rd generation Dodge Cummins, you will want to step back from them.
- They had the least number of sales.
- They received the most unfavorable feedback.
- Having problems with injection system.
- Design of 53 engine units in them. They are, however, thin, and prone to breakage.
- Third generation Cummins costs between $3800 and $20000, which is pricey.
How Much Does a 4th Generation Cummins Cost?
4th Generation Cummins were far superior to those that are present in our list. They had excellent horsepower and torque support and provided an overall satisfied installation.
They price of a 4th Generation Cummins comes around $2000 – $28000, depending upon the model and the type of stock.
Frequently Asked Questions[FAQ’s]
Is Dodge 6.7 Cummins a good engine?
One of the most recent generation engines is the 6.7 Cummins diesel engine. It is a straight-six, 24-valve twin turbocharged that was introduced in 2007 for Dodge Ram pickups. Uplifted B6.7 Cummins engine is still used in Ram 2500 and 3500+ vehicles today.
It has, however, undergone a few improvements throughout the years. As of 2022, the 6.7 Cummins engine produces 400hp and 1000tq.
Many people identify the Cummins brand with some of the greatest light vehicle diesel engines ever built. However, no engine is flawless, including the 6.7 Cummins diesel.
What is high mileage for a 5.9 Cummins engine?
Cummins supplied a 5.9-liter I6 diesel for Ram vehicle purchasers from 1989 to 2006. The pre-1999 – 12 valve Cummins are highly sought after for their dependability. However, most well-preserved 5.9-liter engines require no substantial repair after 300,000 miles.
Some live far longer than others. Some mechanics favor the pre-1998 12V Cummins engines for their simplicity. Some drivers, however, like the power and fuel economy of the subsequent 24-valve 5.9-liter engine.
Most well-maintained 5.9-liter engines provided adequate durability to help Cummins create an impeccable reputation. Cummins has even established a high mileage league for users whose trucks have traveled more than 100,000 miles.
What transmissions does 6.7 Cummins use?
Aisin 6-speed automatic gearbox is one of the transmission options for Ram’s 6.7L Cummins turbocharged engine. This motor generates up to 400 horsepower and 1,000 pounds-feet of clean-diesel performance.
It can pull 31,000 pounds with the Aisin gearbox. Furthermore, the Cummins motor has some of the top fuel economy estimates for engines of its type, and class-leading 15,000-mile oil and filter periods.
6.7 or 5.9? Which to Choose?
Which one is superior has been a popular topic and source of concern? Cummins 5.9 or 6.7? To be frank, the answer is that it varies. Although most of the features in 6.7 are derived from 5.9, there are several variations. Notably, 6.7L engine certainly has greater power. It has 385 horsepower and 900 lb-ft of torque, opposed to the 5.9L’s 325 horsepower and 610 lb-ft.
However, 5.9L gives us more dependability. It also emits less nitrogen oxide and has lower cylinder pressure. 6.7L Cummins, on the other hand, includes EGR and DPF. It can also haul greater weight. And, the geometry turbo technology, on the other hand, is standard on the 5.9L.
From 1989 to the current, Dodge Cummins engines have transformed truck powertrains. Engine, functionality, horsepower, and style of these vehicles have all changed. Over the decades, efficiency has steadily increased.
It is, however, critical to have a purpose (or objectives) in mind when purchasing a Dodge Cummins to reduce your options. Reviews, particularly videos, might also assist you decide which year to buy and which Dodge years of cummins to avoid!