The Best Diesel Engines In the Last Few Decades

Diesel engines have grown significantly in popularity over the last 40 years for several reasons. One is that modern diesel engines are much quieter than those manufactured more than half a century ago, thanks to constantly improving manufacturing methods.

Modern diesel engines also need less maintenance than gasoline engines of similar size. Another reason is that diesel engines are more fuel-efficient than ever; they return much better mileage than their gasoline counterparts. Also, thanks to robust construction and the use of internal components that can withstand heavy-duty usage, diesel engines are also getting tougher and more durable by the day. This article explores some of the best diesel engines manufactured in recent times. 

What is the Best Diesel Engine?

The best diesel truck engines are the ones that check all the boxes as far as desired truck attributes like performance, efficiency, capability, versatility, and reliability are concerned. The engines mentioned below are preferred by many for various applications, e.g., commercial trucks, SUVs, tractors, etc. Each diesel engine offers unique features and technologies that optimize power output, fuel efficiency, and emissions control.  

Chrysler 3.0L EcoDiesel

The Chrysler 3.0L EcoDiesel is an outstanding light-duty engine. It boasts several key features contributing to its performance, efficiency, and reduced emissions.

• Fuel Injection System: High-pressure common rail direct fuel injection (MultiJet II) featuring electronically controlled injector nozzles
• Compression Ratio: 16.0:1
• Turbocharging: Water-cooled variable geometry turbocharger (VGT)
• Glow Plugs: Low-voltage ceramic glow plugs
• Cooling System: Liquid cooling system
• Air Intake System: Turbocharged air intake system
• Cylinder Configuration: V6
• Crankshaft and Pistons: A forged steel crankshaft and lightweight cast aluminum pistons
• Exhaust System: high- and low-pressure exhaust gas recirculation (EGR) system with diesel oxidation catalyst (DOC), diesel particulate filter (DPF), and selective catalytic reduction (SCR) technology
• Lubrication System: Full-pressure lubrication system
• Valvetrain: DOHC 4-valve per cylinder
• Injector Nozzles: Solenoid injectors
• Torque: 420 - 480 lb-ft at 2,000 rpm
• Power: 240 - 260 hp at 3,600 rpm

3.0L Duramax Turbo-Diesel

The Duramax I6 engine is available in select GM light-duty trucks and SUV models.

•         Fuel Injection System: High-pressure common rail direct injection with Denso HP5 injection pump
•         Compression Ratio: 15.0:1
•         Cylinder Configuration: Inline 6
•         Crankshaft and Pistons: Forged steel and aluminum alloy
•         Turbocharging: Garrett VGT with ball bearing
•         Cooling System: Liquid-cooled
•         Valvetrain: DOHC 4- valve x cylinder
•         Exhaust System: A close-coupled exhaust after-treatment network with a cooled EGR system.
•         Lubrication system: Continuous variable displacement oil pump
•         Injector Nozzles: Solenoid-type fuel injectors
•         Power: 277-305 hp at 3750 rpm
•         Torque: 460-495 ft-lb at 1500 rpm

Ford 3.0L Power Stroke

The Ford 3.0L Power Stroke is a polished performer.

•         Fuel Injection System: High-pressure common rail direct injection with Bosch CP4.2 injection pump
•         Compression Ratio: 16.0:1
•         Cylinder Configuration: V6
•         Turbocharging: Honeywell Electrically Actuated VGT, Intercooled
•         Cooling System: Pressurized Series Flow
•         Valvetrain: DOHC 4- valve
•         Exhaust System: Water-cooled EGR system
•         Injector Nozzles: Piezoelectric injectors
•         Power: 250 at 3,200 rpm
•         Torque: 440 lb-ft at 1,750 rpm

6.6L Duramax Turbo-Diesel

This engine is popular in pickups, vans, and medium-duty trucks.

•         Fuel Injection System: High-pressure common rail direct injection with Bosch CP3 pump
•         Compression Ratio: 16.8:1, 17.5:1
•         Cylinder Configuration: V8
•         Turbocharging: Garrett VGT with intercooler
•         Cooling System: Water cooled
•         Valvetrain: OHV 4- valve x cylinder
•         Exhaust System: Cooled EGR with Oxidizing catalyst, DPF
•         Power: 250- 550 hp
•         Torque: 450 - 1050 lb-ft

Cummins 6.7L Turbo Diesel 

Many consider 6.7L Cummins the best diesel truck engine that handles heavy hauls.

•         Fuel Injection System: High-pressure common rail direct injection with Bosch pump
•         Compression Ratio: 17.2:1, 17.3:1, 17.5:1, 19:1
•         Cylinder Configuration: Inline 6
•         Turbocharging: VGT, air-to-air intercooler
•         Cooling System: Water cooled
•         Valvetrain: OHV 4- valve per cylinder
•         Exhaust System: EGR with DOC, DPF, and SCR
•         Power: 350 - 420 hp
•         Torque: 610 - 1,075 lb-ft

Ford 6.7L Power Stroke

The 6.7 Power Stroke has proven to be a very reliable truck engine.

• Fuel Injection: High-pressure common-rail direct injection with Bosch CP4.2 injection pump
• Compression Ratio: 16.2:1
• Cylinder Configuration: V8
• Turbocharging: Garrett single VGT with wastegate and air-to-air intercooler
• Cooling system: Water-cooled
• Valvetrain: OHV 4-valve x cylinder
• Exhaust System: Cooled EGR with DOC, DPF, and SCR
• Power: 475 hp at 2,600 rpm
• Torque: 1050 lb-ft at1,600 rpm

BMW M57 3.0L

It is a very tough, fuel-efficient, and affordable engine.

• Fuel Injection: common rail direct injection with Bosch CP3 injection pump
• Compression Ratio: 16.5-18.0:1
• Cylinder Configuration: Inline 6
• Turbocharging: Single Garrett or BorgWarner twin-turbochargers with intercooler
• Cooling system: Water-cooled
• Valvetrain: DOHC 4 valves per cylinder
• Exhaust System: EGR
• Power: 161–282 hp
• Torque: 258–428 lb-ft

Cummins 5.9L       

The Cummins 5.9-liter is among the most iconic diesel engines in the automotive industry.

• Fuel Injection: High-pressure, common-rail direct fuel injection with Bosch CP3 injection pump
• Compression Ratio: 16.3:1, 17.2: 1
• Cylinder Configuration: Inline 6
• Cooling system: Water-cooled

• Turbocharging: Single turbocharger, air-to-air intercooler
• Valvetrain: OHV, four valves per cylinder
• Power: 325 HP at 2,900 RPM
• Torque: 610 lb-ft @ 1,600 RPM

Isuzu 4HK1-TC 5.2L

It's one of the cleanest truck diesel engines and is ideal for medium-duty vehicles.

• Fuel Injection: Direct injection, high-pressure common rail
• Compression Ratio: 16.5: 1
• Cylinder Configuration: Inline 4
• Turbocharging: Two-stage turbocharged and intercooler
• Valvetrain: SOHC, four valves per cylinder
• Exhaust System: Diesel particulate diffuser system
• Power: 215 hp at 2,500 RPM
• Torque: 520 lb-ft at 1,600 RPM

 Ford 7.3L Power Stroke

Many truck owners still consider the legendary 7.3L Power Stroke the best diesel engine.

• Fuel Injection: Hydraulically actuated electronic unit injection with a high-pressure oil pump
• Compression Ratio: 17.5:1
• Cylinder Configuration: V8
• Cooling system: Water-cooled

• Turbocharging: Garrett fixed-geometry turbocharger
• Valvetrain: DOHC 2-valves x cylinder
• Exhaust System: EGR with DOC, DPF, and SCR
• Power: 275 hp at 2,800 rpm
• Torque: 525 lb-ft at 1,600 rpm

Why Use Mammoth Performance Parts 

You can improve the performance of your diesel engine fitting it with our aftermarket silicone hoses that improve coolant flow for better engine cooling. Our purposefully designed intercooler boot kits are also a must-have if you are thinking about using your diesel engine in high-performance applications. All Mammoth Performance products are designed to directly fit the engines they are meant for, so you won’t need to make additional modifications.  

So, Which is The Best Diesel Truck Engine For You?

The best diesel truck engine for you depends on your needs and preferences. If you want a heavy-duty, high-horsepower engine that can tow over 10,000 pounds at will, the Ford 6.7 Power Stroke turbodiesel engine is a wise choice. On the other hand, if you need a resilient yet affordable workhorse that can handle medium-duty trucking applications, you won’t go wrong with the  Isuzu 5.2L 4HK1-TC engine.