Best Diesel Engine: 5 Most Reliable Picks in 2024

Diesel engines have been known to be the force behind the power and performance of construction equipment and marine vessels for more than ten decades (100 years) now.

The high performance, durability, and efficiency delivered by diesel engines through high torque and increased horsepower are highly crucial for heavy-duty pickup trucks.

Most pickup trucks are now fitted with diesel engines to empower them with high torque levels and horsepower to enable them to accelerate swiftly without any glitches.

 Trucks with diesel engines deliver the optimum level irrespective of the amount of load they are towing. Meanwhile, hybrid pickups are also becoming popular in the automotive industry.

It is crucial to find out the best diesel engine to enable you to choose the truck with any of these types of engines for your industrial activities.

Best Diesel Engine for Pickup Trucks

The following are some of the best diesel engines you can trust to deliver the required level of torque and horsepower for high performance, durability, and efficiency.

Best Diesel Engine

01. 6.7L PowerStroke (Best Ford Diesel Engine)

The power stroke diesel engines used by Ford trucks were manufactured by Navistar International.

However, the Ford 6.7L Powerstroke became the first to be directly manufactured by Ford. This was an attempt to keep the company relevant in the diesel-powered vehicles automotive industry.

The Ford 6.7L Powerstroke diesel engine was designed as a savior for the 6.4L and 6.0L Power Stroke diesel engines, which were somewhat problematic. It became the best diesel engine in Ford.

The Ford 6.7L Powerstroke diesel engine boasted 390 horsepower output, as well as torque up to 735 lb-ft initially. But these figures were upgraded -engine power up to 400 horsepower and torque up to 800 lb-ft after the engine was released.

Now, the most recent 6.7L Powerstroke features an outstanding set of product features/specifications.

Engine Specifications

  • Configuration: V-8
  • Displacement: 6.7L
  • Period: 2011 till date
  • Maximum Torque: 1,050 lb./ft. at 1,800 rpm
  • Maximum Horsepower: 475 horsepower at 2,800 rpm
  • Bore & Stroke: 3.89 by 4.25 inches
  • Weight: 990 lbs – dry
  • Aspiration: Single VGT turbocharger
  • Price: $85,565

02. 6.7L Cummins (Best Diesel Engine for Towing)

Cummins Inc. released the latest B-series diesel engine – 6.9L Cummins, which was intended to be used in the Dodge Ram in 2007. This engine was a replacement for the overstayed 24-valve 5.9L Cummins.

The 5.9L was going to be replaced because it could no longer keep up with the stringent emissions standard that was constantly increased over time.

The 6.9L Cummins supersedes its predecessors in terms of features. They are designed with some of the new features, found only with the best diesel engines, which most truck lovers wouldn’t trade for anything else.

 Engine Specifications

  • Configuration: Inline-6
  • Displacement: 6.7L
  • Years: 2007 – current
  • Max. Torque: 1,075 lb-ft @1,800 rpm
  • Max. Horsepower: 420 hp @ 2,800 rpm
  • Valvetrain: OHV with 2 valves per cylinder
  • Bore x Stroke: 4.21 by 4.88 inches
  • Weight: 1,060 lbs – dry
  • Valvetrain: Conventional pushrod Overheated valve with 4 valves per cylinder
  • Aspiration: Charge Air Cooled &Turbocharged
  • Price: $4,495 upwards

03. Duramax 6.6L L5P (#1 Duramax Engine)

The Duramax 6.6L L5P was introduced by Chevrolet in 2017 to replace the former Duramax LML with a similar displacement. It was introduced as the power-packed diesel engine for the Chevrolet pickups (HD-series), as well as the GMC trucks.

This new 6.6L Duramax diesel engine features upgraded cylinder heads (revised), a sophisticated turbocharger (variable-vane), and an improved camshaft. It also comes with 445 hp, as well as torque up to 910 lb-ft.

This diesel engine comes equipped with the capacity to deliver high performance, durability, and efficiency to enable pickup trucks to tow loads from one place to another without hitches.

Engine Specifications

  • Configuration: V-8
  • Displacement: 6.6L
  • Period: 2017 till date
  • Maximum Torque: 910 lb-ft at 1,600 rpm
  • Maximum Horsepower: 445 horsepower at 2,800 rpm
  • Valvetrain: OHV with 4 valves per cylinder
  • Bore & Stroke: 4.05 by 3.89 inches
  • Weight: Up to 835 lbs – dry
  • Price: $15,000 – $25,000

04. 7.3L Ford Power Stroke (#1 Reliable Diesel Engine)

After several decades, the 7.3L Powerstroke is regarded as the most reliable diesel engine among its sophisticated counterparts. This diesel engine was a product of the joint venture between International Navistar (now Navistar International) and Ford.

The 7.3L Powerstroke diesel engine was manufactured to be used in Ford’s heavy power-packed trucks. The diesel engine was designed with a technology (HEUI) that helped eliminate the need for a solely dedicated injection pump.

In place of the injection pump, high-pressure engine oil created hydraulic pressure in each injector to inject low-pressure fuel under substantial force. The 7.3; Power Stroke was unique and strong enough to overcome loads due to the remarkable features/specifications of the engine.

Engine Specifications

  • Displacement: 7.3L
  • Period: 1994 – 2003
  • Configuration: V8
  • Maximum Torque: 525 lb./ft. at 1,600 rpm
  • Maximum Horsepower:275 hp at 2,800 rpm
  • Valvetrain: OHV with 2 valves per cylinder
  • Bore & Stroke: 4.11 by 4.18 inches
  • Weight: Up to 920 lbs – dry 
  • Price: $10,000 upwards

05. 6.6L Duramax LBZ

The 6.6L Duramax LBZ was manufactured and first used in 2006 to replace the LLY Duramax that was manufactured before it. However, the 6.6L Duramax LBZ was short-lived.

The LBZ Duramax was terminated after the Duramax LMM 2007 model was produced to further replace the LBZ Duramax because of the multiple faults that characterized its use.

One of those multiple faults was an untimely piston failure. It was more or less like a remanufactured engine.

The 6.6L Duramax LBZ had a couple of features that users managed to explore until the LMM Duramax later replaced it in 2007.

Engine Specifications

  • Displacement: 6.6L
  • Period: 2005 – 2007
  • Configuration: V8
  • Maximum Torque: 650 lb./ft. by 1,600 rpm
  • Maximum Horsepower: 360 hp by 3,200 rpm
  • Valvetrain: OHV with four(4) valves per a cylinder
  • Bore & Stroke: 4.06 by 3.90 inches
  • Weight: Up to 835 lbs – dry
  • Price: $15,000 upwards

Other diesel engines with sophisticated designs, features, and specifications that deliver high performance, durability, and efficiency include the following:

  • 5.9L Cummins (24V ISB)
  • 6.6L Duramax LB7 LM2
  • 3.0L Duramax
  • 3.0L EcoDiesel

best diesel engine for 4x4


What is the most reliable diesel engine?

The most reliable diesel engine is the powerful 7.3L Powerstroke. The engine comes with sophisticated features that make it outstanding among other diesel engines. Its features include 235 horsepower and 500 pound-feet of torque.

Ford’s 7.3L diesel engine was already manufactured before some new rules and regulations were introduced to control the pattern adopted for the manufacture of diesel engines. And now they outshine most of their recent diesel engine counterparts.

In terms of reliability, the 7.3L Power Stroke is still the best diesel engine in 2021. Since it was manufactured, it has retained that worth.

The Ford’s 7.3L Powerstroke’s engine block and internal compositions were over-engineered and overbuilt for the capacity of the truck’s power output. The engine is designed with a B50 Life which guarantees it to last about 350,000 miles.

What is the best diesel engine ever made?

Some manufacturers in the automotive industry produce very sophisticated engines, to the point that picking the best engine among others is quite challenging. Just like selecting the best among a series of electric vehicles requires critical analysis of several factors.

However, with critical analysis and surveys to find out what car owners and expert vehicle enthusiasts think about these engines, it is pertinent to list some of the best diesel engines without mincing words. The following engines rank as some of the best diesel engines ever made:

  • Rudolph Diesel’s first working engine
  • Detroit Diesel Series 60
  • VW 5.0L V-10
  • MTU 16V-4000
  • International 7.3L power stroke
  • GM 6.6L Duramax
  • Caterpillar C12 super truck racing engine
  • Wartsila Sulzer RTA96-C
  • International DT466
  • The Cummins B-series

What company makes the best diesel engine?

Some of the companies that manufacture diverse kinds of sophisticated diesel engines with high performance, durability, efficiency, and a touch of excellence include the following:

  • Cummins Inc. (founded by Clessie Lyle Cummin and J. Irwin Miller)
  • General Motors
  • Navistar International (formerly known as International Navistar)
  • DMAX Ltd. (A joint venture between Isuzu and General Motors)
  • Detroit Diesel Corporation (Cited in Detroit, Michigan, United States), etc.

Which is better, Duramax or Cummins?

One of the common yardsticks to measure the superiority of vehicle engines is the horsepower capacity. High horsepower guarantees swift and faster acceleration for vehicles irrespective of whether the vehicle is towing another vehicle.

The 6.6L Duramax L5P engine comes with about 445 hp against the 400 horsepower generated by the latest Cummins 24V Ram 6.7L  diesel engine. This is an advantage that Duramax has over Cummins. However, both diesel engines rank among the best.

What are the worst diesel engines?

Some of the worst diesel engines happened to make the blacklist because of their inability to produce the power required by the vehicles, as well as the minimal level of horsepower needed for fast acceleration and efficiency.

The following diesel engines are some of the worst diesel engines you can ever think of in the automotive industry:

  • VT-265 and VT-335 International DT engines
  • CAT 3116
  • Cummins ISX
  • Old 2-stroke Detroit series 50, V-71 OR V-92 engines, etc.

Some of the engines outlined above were initially okay when they were first manufactured (for example, the VT-265, and VT-335). They became bad when the manufacturers decided to modify them from 6 cylinders to 4 cylinders, thereby altering their power output.

What is the longest-lasting diesel engine?

The longest-lasting diesel engine is the 5.9L Cummins 12-Valve 6BT. The engine possesses million-mile durability, with an outstanding 30 horsepower for fast acceleration. It also features up to 440ft-lbs of torque and a high-performance P7100 injection pump.

The Cummins is known to be the king of torque, ranking higher than Duramax and some other diesel engines. They feature up to 1,000lb/ft of torque.

If you need a diesel engine with a guarantee of longevity, you can’t go wrong by choosing the Cummins 5.0L 12-Valve 6BT diesel engine.

Why is Cummins the best diesel engine?

If you are asking, “Is Cummins the best diesel engine?” There is a reason why truck enthusiasts think Cummins is worth ranking as one of the best diesel engines for pickup trucks.

Cummins Inc. is known as one of the top-rank diesel engine manufacturers in the automotive industry globally. Cummins engines are respected for the level of torque and amount of horsepower they deliver, which guarantees swift acceleration on the road.

Work trucks require a great level of horsepower and torque to enable them to tow heavy loads at any time. This is precisely what Cummins diesel engines deliver: the necessary horsepower and torque.

No wonder Cummins engines are referred to as the king of torque. Cummins retained their position as one of the best diesel engines in 2020 and is up to date.

What diesel engine does Ford use?

Modern Ford trucks are powered by 6.7L Powerstroke engines. This is the fourth generation of engines that the diesel-powered trucks manufactured by Ford are fitted with. Most of the diesel engines for Ford trucks were manufactured by Navistar International.

The first power stroke diesel engine manufactured by Ford officially is the 6.7 Liter V8. Before this diesel engine was produced, other versions of Powerstroke were manufactured by Navistar International (formerly known as International Navistar) for Ford.

Final Words

Pickup trucks are rated most especially by their engine capacity, which is determined by the level of torque and horsepower.

When choosing a pickup truck, identifying the best diesel engines is crucial because the engine is most likely the most important part of this particular type of vehicle.

Remember that a pickup truck’s capacity to carry a load and accelerate at an optimum level is highly dependent on the engine’s torque and horsepower.

Critically consider choosing from any of the heavy-duty pickup trucks’ diesel engines outlined above in this article.

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

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