Diesel engines are like gasoline engines with the difference being the combustion process. 

Also, known as combustion-ignition engines to the combustion process involved to power your truck.

Diesel engines power your vehicle using pistons to pressurize the air in the engine cylinder. 

The pressure heats the air heating it hot enough for diesel fuel to self-ignite. 

They offer a higher efficiency level, more low-end torque and incredible pulling power.

In This Article

The history of the diesel engine starts in 1876 with the invention of gasoline engines by Nikolaus August Otto. 

The gasoline engine used four-stroke combustion referred to as the “Otto Cycle”. 

This cycle is the basic principle for most engines today.

At first, the gasoline engine was very inefficient with only 10% power return from diesel used. 

But in 1878, Rudolf Diesel learned about the inefficiency of gasoline and diesel engines at Polytechnic High School of Germany..

That discovery became his life motivation inspiring Rudolf Diesel to create a more efficient Combustion Powered Engine. 

In 1892, Diesel patented what’s now known as diesel engines or compression-ignition engines.

Four-stroke diesel engines function by repeating a cycle of four stages/strokes. 

The four stages cause the crankshaft to rotate twice sending power to the wheels. 

Thanks to the engine piston moving up and down two times.

Air Intake – Outside air gets drawn into the cylinder through an air inlet valve as the piston moves down.

Compression – The air inlet valve shuts while the piston pushes up. The push compresses the air causing it to reach high heat. 

Then, fuel injectors send diesel fuel through the central fuel injection valve. 

There the fuel combusts on contact with the heated air mixture.

Power – The burning air-fuel mixture pushes the piston down. Which drives the crankshaft, sending power to the wheels.

Exhaust – The waste gas expels through an exhaust valve on the upper left of the diesel engine.

Two-stroke diesel engines function in one cycle that moves the piston up and down. 

Even though labelled as a two-stroke engine there are three stages in the two-stroke cycle.

Air Intake & Exhaust Gases – Outside air blows in the side of the engine cylinder. Which replaces the exhaust gases by pushing them through exhaust valves.

Compression – Air inlet and exhaust valves shut while the piston pushes up. 

This push compresses the air and heats it to high temperatures. 

Once the piston is at the top, fuel injects into the engine cylinder which combusts on contact.

Power – While the air-fuel mixtures burns, the piston pushes down. 

The push rotates the crankshaft which sends power to the wheels.

The highest-rated turbo-diesel Powerstroke engine was the 7.3L Powerstroke. 

But, in 2003 Ford ended production of the 7.3L Powerstroke diesel engines. 

The production had to stop due to new emissions standards.

Now the Powerstroke diesel engine rated highest is the third-generation 6.7L Powerstroke. 

It has a ten-speed automatic transmission that’s capable of over 450 horsepower. Also, producing up to 1050lbs of torque.

This engine has incredible pulling power rated at 37,000lbs. 

That puts the 2020 Ford Super Duty at the top of its class in towing capacity.

The third-generation 6.7L Powerstroke diesel engine was released in late 2019. 

It brought the newest hardware available when it entered the 2020 heavy-duty engine scene. 

The newest diesel engine hardware that includes:

  • Compacted Graphite Iron Block
  • Stronger Crankshaft
  • Aluminum Cylinder Heads
  • Improved Bears
  • Completely Redesigned Intake Manifold
  • Electronic Turbo-Charger
  • Bosch Diesel Fuel Injectors set to 36,00psi injection pressure

Third-Generation 6.7L Powerstroke Diesel Engine Specifications

  • Displacement – 6.7L (406 ci)
  • Configuration – V8
  • Horsepower – 450hp @ 2800 rpm
  • Torque – 1050lbs/ft @ 1800 rpm
  • Turbocharging – Single Variable-Geometry Turbocharger
  • Bore x Stroke – 3.90 x 4.25 inches
  • Compression Ration – 16:2:1
  • Valvetrain – OHV w/ Four Valves Per Cylinder
  • Engine Head Material – Aluminum Alloy
  • Engine Block Material – Compacted Graphite Iron
  • Transmission – Ten-Speed Automatic

The highest-rated Cummins diesel engine is the 6.7L Cummins I-6. 

The 6.7L Cummins I-6 heavy-duty diesel engine provides 400 horsepower and 1000lb/ft of torque. It has a towing capacity of up to 35,100lbs.

It’s available as a smaller diesel engine for light-duty pickup trucks. with 370hp and 850lb/ft of torque.

2020 6.7L Dodge Ram Cummins Engine Specifications

  • Engine – Cummins B-Series
  • Displacement – 6.7L (408 ci)
  • Configuration – I-6
  • Power – 370hp @ 2800 rpm (68RFE Automatic Transmission)
  • Torque – 850lb/ft @ 1700 rpm (68RFE Automatic Transmission)
  • Power – 370hp @ 2800 rpm (AS69RC Automatic Transmission Ram 3500 Only)
  • Torque – 850lb/ft @ 1700 rpm (68RFE Automatic Transmission Ram 3500 Only)
  • Turbocharging – Single Variable-Geometry Turbocharger
  • Bore x Stroke – 4.21 x 4.88 inches
  • Compression Ratio – 16:2:1
  • Valvetrain – OHV w/ Four Valves Per Cylinder
  • Engine Head Material – Cast Iron
  • Engine Block Material – Cast Iron
  • Transmission – Six-Speed Automatic

The best Duramax diesel engine is the 6.6L Duramax L5P V8. 

It’s featured in the 2020 Chevy Silverado 2500HD, 3500HD and the 2020 GMC Sierra Heavy-Duty.

The 6.6L Duramax L5P V8 has 445 horsepower and 910lbs/ft of torque. 

New to the 2019 6.6L Duramax L5P V8 is an Allison ten-speed automatic transmission. The combination brings a huge increase to performance and efficiency.

Even though the 6.6L Duramax has a lower torque than other diesel engines. The combination of the 6.6L Duramax L5P V8 and Allison 10L1000 gearbox increases towing capabilities. 

The combination of the diesel engine and gearbox has a towing rating that’s rated for up to 35,500lbs.

2020 6.6L Duramax L5P V8 Diesel Engine Specifications

  • Engine – Duramax L5P
  • Displacement – 6.6L (403 ci)
  • Configuration – V8
  • Power – 445hp @ 2800 rpm
  • Torque – 910 lb-ft @ 1600 rpm
  • Turbocharging – Singe Variable-Geometry Turbocharger
  • Bore x Stroke – 4.05 x 3.89 inches
  • Compression Ratio – 16:0:1
  • Valvetrain – OHV w/ Four Valves Per Cylinder
  • Engine Head Material – Cast Aluminum
  • Engine Block Material – Cast Iron
  • Transmission – Ten-Speed Automatic

The most reliable diesel engine ever made was the 5.9L Cummins 12-Valve 6BT. 

The 5.9L 12-Valve has million-mile durability. It came factory with a 230hp, 440lb/ft of torque and an inline P7100 injection pump.

Diesel enthusiasts driving in the era of the 5.9 Cummins 12-Valve diesel engine. They could increase horsepower to over 500hp with ease.

The 5.9L Cummins 12-Valve had an outstanding performance and fuel efficiency rating. 

It is almost guaranteed to last over 500,000 miles.

Its fuel consumption rate was about 20 mpg while highway driving.

The highest-rated eco-friendly diesel engine is the 3.0L Power Stroke V6 Turbo-Diesel. 

It has an EPA-estimated highway fuel economy of 30mpg and a city fuel economy of 22mpg.

The 3.0L Power Stroke V6 turbo-diesel has a rail fuel injection system with 29,00psi injection calibration. 

It has great power and torque for light-duty trucks with 250 horsepower and 440lb/ft of torque. 

Also, the diesel engines max towing capacity is 11,400bs with a payload capacity of 1940.

Ford 3.0L Power Stroke Turbo-Diesel V6 Specifications

  • Engine – 3.0L Power Stroke (3.0L TDCI)
  • Displacement – 3.0L (183 CID)
  • Configuration – V6
  • Power – 250hp @ 2800 rpm
  • Torque – 400 lb-ft @ 1600 rpm
  • Turbocharging – Singe Variable-Geometry Turbocharger
  • Bore x Stroke – 3.307 x 3.543 inches
  • Compression Ratio – 16:0:1
  • Valvetrain – Dual Overhead Camshaft (DOHC) Four Valves Per Cylinder
  • Engine Head Material -Aluminum Alloy
  • Engine Block Material – Compacted Graphite Iron
  • Transmission – Ten-Speed Automatic

The highest-rated overall best diesel engine available in 2020 is the 7.3L Power Stroke Turbo-Diesel.

It comes standard on all 2020 Ford Super Duty pickup trucks. It provides over 450 horsepower and 1050lbs/ft of torque. 

The Super Duty has a towing rating up to 37,000lbs making it an absolute workhorse.

2020 Ford Super Duty 7.3L Powerstroke diesel engine TrucksResource

The reason that a diesel engine makes so much noise while burning fuel the molecule size. 

Diesel fuel has larger molecules than gasoline that are getting compressed. 

Also, there’s a lot of clattering noise created from the compression, heat and self-igniting fuel.

Diesel engines do not have spark plugs. 

Instead, compression motors give a slower burn that gives less stress and more torque. 

In turn, increasing diesel engine performance.

Diesel engines last longer than gasoline for many reasons:

Diesel Engine Design – Diesel engines have larger crankshafts and camshafts. Allowing better oil flow which promotes engine lubrication. 

Also, they have higher compression ratios and cylinder pressures.

Properties of Diesel Fuel – Diesel is a distillate fuel made from crude oil and extends engine life. 

Diesel fuel burns at a much leaner air to fuel ratio. The combustion produces exhaust gases that help with lubrication.

Engine Fan Rotation Per Minute -Diesel engines have high operating efficiency. Diesel engines run at a lower RPM than gasoline engines. But, they produce more horsepower and torque.

They operate at lower speeds to achieve higher performance. This has less impact on all the engine components.

When starting a diesel engine during the colder season plug in your block heater. 

But, before starting your truck make sure that you unplug the block heater.

Now that the diesel pickup truck is ready to start, turn the key to the run position. But, don’t start the truck yet. 

Instead, pay attention to the dash lights and gauges. Watching for the glow plug heating indicator light to go out. 

Then, you can turn the key and start the vehicle.

Setting your diesel vehicle to run before starting it allows fuel to pump and the glow plugs to warm up.

There are many ways to reduce the noise produced from your diesel engine:

Switch to Synthetic Oil – Synthetic oils that include Teflon (PTFE) improve lubrication between moving parts. 

The added lubrication reduces friction and noise.

Add Oil-Based Additives – The addition of an additive to your engine oil will coat the moving parts. 

Lowering engine noise by reducing friction.

Install an Engine Shield or Cover – These are great for reducing engine heat and quiet the noises. 

But, be sure to add a noise-dampening material to the bottom side.

Proper Cetane Diesel Fuel – When filling your diesel vehicle be sure to buy the correct cetane number diesel for a quieter ride.

Replace Door & Window Rubber Seals – Switch the factory door and window seals on your vehicle with noise-isolating ones.

The main cause for the black smoke produced by diesel engines is an incorrect air to fuel ratio. 

This happens when the diesel fuel injectors are sending too much fuel or there isn’t enough air intake.

The black smoke that diesel engine pickups produce is often referred to as rolling coal.

Yes, diesel engines can use ethanol to power them. This is thanks to the creation of Ethanol-Diesel Blends. 

E-Diesel is a new fuel source that consists of up to 15% ethanol mixed with diesel.

E-Diesel reduces the number of hazardous diesel emissions released into the atmosphere.

Does a Diesel Engine Need to Warm Up Before Driving?

Diesel engines won’t reach their ideal operation temperatures until they’re in motion and under load. 

But, with that said a diesel engine should idle for 30 seconds to circulate the oil before driving off.