Best Diesel Engine – A Complete Guide

For almost a century, diesel engines have been the driving force behind the power and performance of construction equipment and marine vessels. Diesel engines’ high torque and horsepower give great performance, durability, and efficiency, which is critical for heavy-duty pickup trucks. Most pickup trucks are now equipped with the best diesel engine, which provides them with tremendous torque and horsepower, allowing them to accelerate quickly and smoothly.

Diesel-powered trucks provide the best performance regardless of the load they are towing. Meanwhile, hybrid trucks are gaining popularity in the automobile industry.  It is critical to determine the best diesel engine so that you can select a truck with one of these engines for your needs.

If you’re wondering whether diesel or a gasoline engine is better, we’ve got you covered. This article will guide you in the correct way if you are concerned about fuel efficiency, dependability, or any other characteristic. There is no such thing as a flawless engine, but some are unquestionably superior to others.

The Duramax 6.6-liter (Chevy/GM), Cummins 6.7-liter (Dodge), and Powerstroke 6.7-liter diesel engines are widely regarded as the best diesel engines for pickup trucks in 2022-2023.

• What is the Best Diesel Engine?
• Factors to Consider?
• Diesel Vs Gas Engines?
• Best Diesel Engine?
• Final Verdict

What Is The Best Diesel Engine?

Here’s how to determine which is the best diesel engine:

• Maximum power output
• Torque peaks (towing capacity)
• Fuel economy
• Durability
• Longevity

When it comes to comparing engines, horsepower is a popular criterion. The highest horsepower is the subject of much discussion. When the engine reaches a specific number of revolutions per minute, it reaches its peak horsepower (rpm). The purpose of an engine is to generate and deliver power to the truck. In general, more horsepower correlates to better acceleration and top speeds.

Torque is another way of measuring power. Torque is the force required to propel a truck from a stop and lift hefty loads. It is measured in pound-feet. At 3,200 rpm, the Duramax 6.6-liter diesel engine produces 360 horsepower and 650 pound-feet of torque at 1,600 rpm. At 2,800 rpm, the Cummins 6.7-liter produces 385 horsepower and 865 lb-ft of torque at 1,700 rpm. The Powerstroke has 275 horsepower at 2,800 rpm and 525 pound-feet of torque at 1,600 rpm.

Remember that while fuel economy saves money on gas, it is also more expensive. A number of other factors also influence your vehicle’s fuel efficiency. Your vehicle will be less fuel-efficient if you put an engine in it with a crew cab, extended bed, and other similar upgrades.

The selection of an appropriate task is more important than the machine’s efficiency. If you choose the best diesel engine for your needs, you’ll never be disappointed. As a result, knowing which style is suitable for a certain application is crucial. To make the best decision, it would be ideal if you compared these engines.

We will compare gas and diesel engines so you can pick the best one for you. Before we go into that, let’s go through some of an engine’s benefits and drawbacks:

Aspects To Consider

• A charge of gasoline and air is sucked into the cylinder during the suction stroke of a gas engine and then compressed during the compression stroke. Compression elevates the temperature over the fuel’s ignition threshold, allowing for pre-ignition in gasoline. Only air is compressed during the compression stroke in a diesel engine, and fuel is pumped subsequently.
• A carburetor is used in a gas engine to supply the right quantities of air and gasoline. An injector or atomizer injects gasoline near the end of the compression stroke in a diesel engine.
• Diesel engines are larger and more powerful than gasoline engines. As a result, the initial cost, as well as the cost of repair, are higher. A higher grade of material and workmanship is expected due to the high compression ratio.
• While a diesel engine has a higher initial cost, it can run for nearly twice as long on the same quantity of fuel as a gasoline engine. Operating costs are reduced since diesel is less expensive than gasoline. This is favored over a gasoline engine for any form of a hard task.
• There is no need for an extra heat source because compressed air heat is used to burn the fuel in diesel. A spark plug is required in gas to ignite the charge with an electric spark.
• Engines that run on gasoline are more prone to catching fire than diesel engines.
• Because of the increased compression ratio, which demands more cranking effort, diesel engines are more difficult to start.
• Gas engines outperform diesel engines under lesser loads because of improved fuel and air mixing.
• Diesel engines have a higher thermal efficiency than gasoline engines due to their high compression ratio.
• The Otto cycle is used by the gas engine, while the diesel engine uses the Diesel cycle.

Diesel Vs. Gas Engines: What’s The Difference?

While both gasoline and diesel engines are internal combustion engines, the manner in which the combustion process takes place is what distinguishes the two.

• Fuel and air are combined before pistons compress them and spark plugs ignite them in a gasoline engine.
• Before injecting fuel into a diesel engine, the air is compressed. As the gasoline is squeezed, it warms up and ignites.

Both diesel and gasoline engines use a four-stroke combustion cycle, however diesel engines do not use spark plugs. Let’s take a deeper look at some of the best diesel engines on the market now that you know a little more about the differences between diesel and gas engines.

Best Diesel Engine For Autos

The engines listed below are some of the best diesel engines you can rely on to produce the necessary torque and horsepower for great performance, durability, and efficiency.

1. Best Diesel Engine – V8 Duramax 6.6 Turbo Diesel

This year marks the 20th anniversary of the Duramax 6.6L V8 turbo-diesel engine, which is now in its sixth generation (called L5P). The current iteration, which debuted in 2017, roughly doubled the power and torque of the previous generation, going from 235 horsepower and 500 lb-ft to 445 horsepower and 910 ft-lb. All of this while lowering exhaust emissions. There are almost 1,000,000 Duramax engines on the road today.

Duramax diesel engines produce a lot of power and retain a high level of efficiency throughout your journey. It takes 7.1 seconds to accelerate from 0 to 60 mph in a GMC Sierra 2500HD Crew Cab 4WD. The engine can produce more power at lower cylinder pressure due to a sophisticated variable-vane mechanism.

A new vehicle air intake system draws cool air into the engine with a hood scoop. This improves the engine’s performance, especially when towing or driving up steep gradients. The car is slowed by an exhaust brake, which reduces wear and tears on the vehicle’s standard braking system.

Overheating, premature injector failure, chafing of the injector harness, and a limp transmission mode that occurs at random are all problems with the engine. Potential problems include engine oil being placed wrongly in the turbocharger, erroneous air in the fuel lines, and fuel starvation.

Specifications Of The Engine

• V-8 configuration
• 6.6L displacement
• From 2017 to the present
• At 1,600 rpm, the maximum torque is 910 lb-ft.
• At 2,800 rpm, the engine produces 445 horsepower
• OHV with four valves per cylinder valvetrain
• 4.05 by 3.89-inch bore and stroke
• Dry weight up to 835 lbs
• Price ranges from $15,000 to $25,000

2. Best Diesel Engine – I6 Cummins Turbo Diesel

The Cummins I6 turbo diesel is a straight-six, 24-valve engine that has been modified for better responsiveness and handling. These enhancements are made possible by minimal noise and vibration. This engine is the most powerful in terms of torque and towing capacity. Cummins has attained 1,000 lb-ft of torque in 2019 and can tow 35,100 pounds and lift 7,680 pounds.

The I6 is an inline engine, while the others are all V8s. Inline engines are simpler than V8s since they only have one cylinder head and one valvetrain. There is also a more significant area inside the engine compartment, making repairs and maintenance easier. It comes with an Aisin AS69RC six-speed automatic transmission and comes in 4×2 or 4×4 versions.

Emissions elements, such as a clogged diesel particulate filter (DPF), EGR (exhaust gas recirculation), or fuel dilution, are frequently the source of problems with the Cummins 6.7. It’s also been stated that the turbo and head gaskets have failed.

Specifications Of The Engine

• Inline-6 is the configuration
• 6.7L displacement
• 2007 to the present
• Maximum torque: 1,075 lb-ft at 1,800 rpm
• Horsepower maximum: 420 horsepower at 2,800 rpm
• OHV with two valves per cylinder valvetrain
• 4.21 x 4.88 inches Bore x Stroke
• Dry weight: 1,060 pounds
• Pushrod valve train 4 valves per cylinder overheated valve
• Charge aspiration Turbocharged and air-cooled
• Price range: $4,495 and higher

3. Best Diesel Engine – 6.7L Powerstroke

Ford released a new Powerstroke engine in 2011, the same year Chevy and GM debuted the Duramax engine. This new engine was built without the help of Navistar, Ford’s previous engine partner. A steel crankshaft, a water-to-air intercooler, the Instant Start feature, and a common-rail injection system are all included in this engine.

It also has a compressed and deep-skirt graphite iron engine block with innovative piston jets that cool engine components and extend their lifespan. The weight of this component is lower than that of previous models.

An IROX coating on the lower main bearing, a larger crankshaft damper, a fan clutch update, an EGR cooler flow, and turbo modifications to support increased power and torque are among the other improvements over prior models. CP4 Bosch pump failures, which contaminate the entire fuel system with metal shavings, are a problem with the Powerstroke.

Repairing this issue could cost you up to $9,000 in total. Other difficulties include air entering the fuel system during a fuel filter change, the truck shifting into neutral for a second or two, the fan clutch failing to turn on at high temperatures, and the truck shaking for no apparent reason during regular operation. Truck owners refer to this well-known problem as “death wobble.“

However, if you drive a larger pickup truck, you now have three engine alternatives that are long-lasting, dependable, and will keep you out of the shop for expensive repairs.

Specifications Of The Engine

• V-8 configuration
• 6.7L displacement
• From 2011 to the present
• At 1,800 rpm, maximum torque is 1,050 lb/ft
• At 2,800 rpm, the engine produces 475 horsepower
• 3.89 by 4.25-inch bore and stroke
• Dry weight: 990 pounds
• Single VGT turbocharger for aspiration
• $85,565 is the price.

4. Best Diesel Engine – Ford PowerStroke 7.3L

The 7.3L Powerstroke is recognized as the most reliable and best diesel engine among its sophisticated contemporaries after several decades. The joint venture between International Navistar and Ford produced this diesel engine. Ford developed the 7.3L Powerstroke diesel engine specifically for its heavy-duty trucks. The diesel engine was built with HEUI technology, which eliminated a dedicated injection pump requirement.

Instead of using an injection pump, high-pressure engine oil was used to create hydraulic pressure in each injector, allowing low-pressure fuel to be injected with significant force. The 7.3; Power Stroke was distinctive and strong enough to overcome loads due to its excellent features and characteristics.

Specifications Of The Engine

• 7.3L displacement
• V8 configuration
• At 1,600 rpm, the maximum torque is 525 lb/ft
• At 2,800 rpm, the engine produces 275 horsepower
• OHV with two valves per cylinder valvetrain
• 4.11 by 4.18-inch bore and stroke
• Dry weight: up to 920 pounds
• Price range: $10,000 and above

5. Best Diesel Engine – Duramax LBZ 6.6L

The 6.6L Duramax LBZ was introduced in 2006 to replace the previously available LLY Duramax. The 6.6L Duramax LBZ, on the other hand, was only around for a few months.

Because of the numerous flaws that characterized its use, the LBZ Duramax was discontinued after the Duramax LMM 2007 model was introduced to further replace the LBZ Duramax.

An untimely piston failure was one of the several issues. It appeared to be a reconditioned engine. Users were able to explore a few aspects of the 6.6L Duramax LBZ until the LMM Duramax superseded it in 2007.

Specifications Of The Engine

• 6.6L displacement
• 6.6L displacement
• V8 configuration
• 650 lb./ft. maximum torque at 1,600 rpm
• 360 hp at 3,200 rpm maximum horsepower
• OHV with four valves per cylinder valvetrain
• 4.06 by 3.90-inch bore and stroke
• Dry weight: up to 835 lbs.
• Price range: $15,000 and above

6. Best Diesel Engine – 855 Big Cam Cummins

In 1976, Cummins released the 855 Big Cam, the company’s last mass-produced true mechanical variable-timing engine. Cummins’ Big Cam engine, which replaced the 855’s small cam, was the first to comply with the period’s Clean Air Act and noise requirements. The Cummins Big Cam 855 engine was produced for four generations before being replaced in 1985 by the N14.

Because of its raw horsepower and dependability, the 855 Big Cam is the best diesel engine. Before needing to be rebuilt, a Cummins 855 Big Cam will safely travel 700,000 miles. The Cummins 855 Big Cam was the first engine in the company’s lineup to incorporate demand-flow cooling, which cools the engine only when it needs it.

The horsepower saved at the crankshaft is then used to boost the engine’s horsepower.

The Big Cam II considerably enhanced performance by adding pulse manifolds into the engines; this was a major selling feature for these engines at the time. This engine’s overall horsepower was the main reason it outsold the small cam engines.

Top-stop injectors and one of the largest camshaft diameters on the market at the time were features of the Cummins 855 Big Cam. Any 1970s truck driver will tell you how the Cummins 855 series was the road king. These engines are tough to leave off any list of the top diesel engines of all time. The 855 had a few problems, particularly when it came to starting the engine in cooler temperatures.

To control the injectors and changing timing requirements, oil/water pump, and valve spring pressures, the 855 has a lower pressure fuel injection system with 2,200 psi. However, a glow plug or a shot of ether should suffice to resolve this tiny issue, as the engine is otherwise wonderful.

Specifications Of The Engine

• Four Stroke, Six Cylinder, Inline
• Bore and Stroke: 5.50×5.98 in
• Displacement: 856 ci (14 L)
• Turbocharged aspiration
• Unit fuel injection is the method of delivering fuel
• 10:1 compression ratio
• Up to 605 horsepower in maximum power
• Up to 1,118 lb-ft of maximum torque
• 1,800 rpm is the regulated speed.

7. Best Diesel Engine – 3.0L EcoDiesel Chrysler

The 3.0L EcoDiesel engine impressed in the 2014 Ram 1500 and Jeep Grand Cherokee, becoming the first factory-direct diesel engine in a 1/2-ton pickup in almost a decade. The 3.0L EcoDiesel is manufactured in Cento, Italy, by VM Motori, an Italian manufacturer, and current FCA affiliate.

Although the EcoDiesel engine is still available in the Ram 1500, it has been phased out on Jeep Grand Cherokee applications as of the 2019 model year. The 3.0L EcoDiesel was introduced in 2014 for Ram 1500 and Jeep Grand Cherokee models.

As the name implies, it is extraordinary in terms of fuel efficiency and pollution requirements. A cooled diesel exhaust catalyst (to learn more, check out our guide on what are catalytic converters and what is a catalytic converter made of), as well as exhaust gas recirculation and a beautiful click diesel particulate filter, are among the pollution controls.

This engine is, in reality, one of the few light-duty diesel engines ever built, and it may be the only one available today. The 3.0L EcoBoost is recognized globally and built to produce outstanding gas mileage while still having a reasonable level of pulling power.

Features Of The Engine

From 2014 to 2019, this four-cylinder diesel engine was rated at 240 horsepower and 420 lb-ft of torque. This engine is a V-6 that produces 240 horsepower at 3,600 RPM and 420 pound-feet of torque at 2,000 RPM, with a bore and stroke of 3.27×3.6. A DOHC valve train with four valves per cylinder and high-pressure common rail fuel injection are among the special characteristics.

This engine can tow up to 9,200 pounds and carry up to 1,620 pounds of payload with all of the power. The EcoDiesel was revised for 2020 due to competition from General Motors and Ford Motor Company, increasing power by 20 horsepower and torque by 60 lb-ft while also boosting fuel economy ratings for both two- and four-wheel-drive models.

It has a water-cooled variable geometry turbocharger, like a number of the other best diesel engines on this list. All of this is supported by a durable aluminum alloy head and a compressed graphite iron block. A solid, sturdy bedplate adds even more strength to the block. In comparison to other diesel engines, the engine is somewhat narrow (at 60 degrees for the V-shaped block).

This narrow-angle reduces block mass, improves fuel efficiency, and saves room in the engine bay. Technically, this engine was designed by Cummins and built by VM Motori. However, it is sold in the United States as a Chrysler engine and is also known as the “Ram 1500 3.0L engine.”

Specifications Of The Engine

• 3.0L
• V-6 layout
• Torque: 420 lb-ft
• Power: 240 hp
• DOHC with four valves per cylinder valve train
• Weight of the engine: 505 lbs.
• 3.276.30 inch bore and stroke
• Turbocharged and intercooled aspiration.

Diesel Truck Engines and Their Specifications: Facts

• The article presents a list of the best diesel engines in modern-era pickup trucks.
• The 3.0L EcoDiesel, produced by VM Motori and used by Chrysler, is the industry’s only light-duty diesel engine and has 240 horsepower and 420 lb-ft of torque.
• The 5.9L, 12-valve Cummins engine is considered to have started the modern-era, turbodiesel-pickup movement, and it produced 160 horsepower and 400 lb-ft of torque for the First Gen (1989-1993) and 245 hp/505 lb-ft for the Second Gen (1994-1998).
• The latest version of the 6.7L Cummins engine (2015 High Output) offers 385 horsepower and 865 lb-ft of torque in 1-ton Ram 3500s equipped with Aisin’s AS69RC automatic transmissions, the most torque ever available in a civilian pickup truck.
• The 5.0L Cummins engine is considered as being able to be fuel-efficient while being capable of doing real work, producing 310 horsepower and 555 lb-ft of torque.
• The ’06-’07 6.6L Duramax LBZ by General Motors is a modifier’s dream, with a stronger block, larger connecting rods, new pistons, lower compression, and cylinder heads that are less susceptible to cracking under extreme pressure, while producing 360 horsepower and 650 lb-ft of torque.
• The ’08 6.4L Power Stroke by Ford represents the company’s focus on improving the nuances of its 6.0L predecessor, with a reconfigured cylinder-head bolt pattern, common-rail fueling, and sequential/twin turbocharging. It produced 350 horsepower and 650 lb-ft of torque.
• The 6.7L Power Stroke by Ford produced 440 horsepower and 860 lb-ft of torque.
• The 7.3L Power Stroke by Navistar/Ford produced 275 horsepower and 525 lb-ft of torque and is a legendary powerplant founded on the International/Navistar T44E.
• The article acknowledges that declaring the “best” engines is a tricky task, as there are several facts about certain diesels that support their inclusion.

Final Verdict:

If you need to buy a diesel engine and are unsure which one to choose, you understand how critical selecting the best diesel engine is. You won’t get very far without the right diesel engine, whether you need a lot of power or a lot of dependability. These engines are essential for medium to heavy-duty applications, ranging from off-roading to hauling huge goods. The best diesel engine can execute all of the tasks necessary for safe transportation.

Choosing the best diesel engine ensures that you will have a long-lasting and efficient engine. Here, we’ve listed the best diesel engine currently on the market, all of which are good selections for your vehicle.

You can choose the appropriate one based on your budget. We’ve also listed the advantages and disadvantages of these diesel engines, as well as their specifications and basic descriptions. We’ve also looked at a variety of important factors to consider when selecting the best diesel engine from various angles.