Best Diesel Engine: 5 Most Reliable Picks in 2023 | Rx Mechanic (2024)

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Best Diesel Engine: 5 Most Reliable Picks in 2023 | Rx Mechanic? ›

The 7.3L Powerstroke is still considered one of the most reliable diesel engines ever made. It also has plenty of power for most applications, with 500 pound-feet of torque and 235 horsepower. It was built for the long haul, too with an air-to-air intercooler, oil-based fueling, and durable internal hard parts.

The 7.3L Powerstroke is still considered one of the most reliable diesel engines ever made. It also has plenty of power for most applications, with 500 pound-feet of torque and 235 horsepower. It was built for the long haul, too with an air-to-air intercooler, oil-based fueling, and durable internal hard parts.

Like Duramax engines, Cummins engines have a reputation for being long-lasting. So what's high mileage for a Cummins diesel engine? These engines can typically last 300,000 to 350,000 miles, which is considered high mileage –but a well-maintained Cummins engine can reach up to 500,000 miles.

Both trucks share similar truck numbers but differ in output, with the Powerstroke coming on top. The Cummins also uses the single sequential turbocharger, but it is different from that of the Powerstroke engine. In terms of performance, the 6.7 Powerstroke engine offers the best.

Filling up with diesel 10ppm

Both 10ppm and 50ppm diesel are considered more refined than diesels with a higher ppm, which means that your engine will run more efficiently, causing less wear and tear on your vehicle. Newer, more complex and efficient vehicle engines can only run on lower-ppm diesel.

What is the maximum efficiency an engine can achieve? The diesel engine has a theoretical system efficiency of between 55-60%.

According to both J.D. Power and Consumer Reports, Toyota constantly figures in the top places as the most dependable brand in the automotive world. Granted, those data pools include far more than simple engine reliability but that feels like a point for Toyota rather than one against it.

What is the life expectancy of a 6.7 Powerstroke? ›

After years of production, the 6.7L Power Stroke has proven it can storm past the 200,000-mile mark with few repairs. Provided you adhere to Ford's recommended service intervals, there is no reason this engine won't see 300,000 or even 400,000 miles.

The safest Duramax model years you can buy are the models produced from 2011 to 2021. These include the Duramax LGH, Duramax LML, Duramax XLD25, Duramax XLD28, Duramax LWN, Duramax L5P, and Duramax LM2. These engines go a step further to provide better emissions thanks to a diesel exhaust fluid/urea injection feature.

Both the 6.6L Duramax and 6.7L Power Stroke are V8 engines, with the 6.7L Cummins being an inline six-cylinder diesel engine. Horsepower and torque numbers are similar between the three diesel engines, but the Cummins engine leads the pack with its torque rating breaching the four-figure threshold.

Verdict. When it comes to towing, Cummins engines are king. However, most passenger and light work trucks don't need to tow as much weight as a Cummins engine can. To meet your average, everyday needs, both Cummins and Duramax engines are capable of giving you enough towing power.

PACCAR engines are considered by far the most reliable diesel semi truck engines. They are used by only two truck brands: Kenworth. Peterbilt.

The 7.3 Ford Power Stroke engine is legendary in diesel circles. It is one of the main reasons the 1999 to 2003 Ford Super Duty trucks are still so popular today. Its reliability is unsurpassed and was produced just before emissions regulations added to diesel engines' cost, complexity, and reliability.

In summary, while all three brands manufacture diesel engines, they each have their own specialties and reputations. Detroit Diesel is known for reliability, Cummins for fuel efficiency and performance, and Caterpillar for durability and performance in heavy equipment.

But an amazing fact is that diesel engines can run for 1,000,000-1,500,000 miles before needing any major diesel repairs. If kept well-maintained, a diesel engine can be driven for about 30 years or more.

Maintenance Is Important to Longevity

That said, while most gas engines are intended to last at least 200,000 miles on average, a diesel truck that is well-maintained can potentially last 350,000 to 500,000 miles.

We recommend staying away from the 1991, 1992, 1993, 1999, 2001, 2003, 2006, 2007, 2008, and 2011 models. Many issues stem from these years. A few of the common appear in the format of transmission failure, charging system troubles, and electrical issues.

Should I buy a Power Stroke or Cummins? ›

The Power Stroke has more horsepower but slightly less torque, while the Cummins has the opposite. However, as noted by AutoWise, the Power Stroke ultimately produces more horsepower, which is a better indicator of engine strength in real driving situations.

Diesel #1 is also known as winter diesel because it performs better than Diesel #2 in cold temperatures. It has a lower viscosity and is not prone to gel in freezing temperatures. Most stations offer a premium Diesel mix that is blended for local weather conditions.

This jaw-dropper is the Wärtsilä RT-flex96C, the world's largest and most powerful diesel engine. Built in Finland, the RT-flex96C's fourteen cylinders can generate 107,389HP with more than 7,000,000Nm of torque — that's enough to power an entire suburban town.

As a general rule of thumb, if it is below zero degrees Fahrenheit, you should allow your engine up to seven minutes to warm up. If the temperature is between zero and fifty degrees, the warm-up period should be three to five minutes. Over fifty degrees will only require one or two minutes to warm up.

You should only buy the 6.7 from 2015 onward. The problems discussed below plagued the first generation of 6.7 Powerstroke engines from 2011 to 2014. What is this? In 2015 Ford redesigned everything that was causing problems, and the 6.7 is now a reliable engine many people love and rely on for daily work.

Digital Trends reports that diesel engines tend to be more durable and last longer than gas engines, with reliable operation and minimal required maintenance. While diesel cars once weighed much more than comparably sized gas vehicles, this is no longer an issue, thanks to modern manufacturing methods.

The 2021 Sierra HD series includes a diesel engine at the 2500 level that's capable of generating 445 horsepower and 910 pound-feet of torque. This Duramax 6.6-liter V-8 gets 17 to 19 mpg on the highway.

The Chrysler 426 Hemi is one of the rarest and most collectible engines on this list, but it also has the distinction of being one of the longest-lasting. The 426 Hemi was an option for owners of large, heavy cars built by Chrysler in the 1960s. The Chrysler 426 Hemi is a legendary engine.

The three winners, Moran Motorsports (Race), LinCo Diesel Performance (Diesel) and Workshop 5001 (Vintage), accepted their awards during Engine Builder's PRI Party, sponsored by Autolite, at Tin Roof in Indianapolis on December 8.

Which engine lasts longer? ›

Another reason diesel engines last longer than gas engines is due to the fuel that they burn. Diesel fuel is a type of distillate fuel that is essentially produced from crude oil, which gives diesel engines slower cylinder wear than gasoline engines.

Injection Pump Failure Leads to Numerous Potential Problems

In the 6.7 diesel engines, the pumps lack adequate lubrication and causes metal to rub against metal. Fragments then make their way into the injection systems and engine. Metal contamination can damage the fuel system, lines, injectors, and regulators.

6.7-Liter Power Stroke V8

That said, the years you may want to avoid are from 2011-2014, as these were known to have emissions and EGR problems, as well as turbo failures.

Not Enough Power to Hurt Itself

Robust, iron parts, conservative power and low engine speed are the key ingredients for any diesel engine lasting forever—and if a 7.3L has gone unmodified yet been well maintained its entire life, 400,000 to 500,000 miles is virtually guaranteed.

LinCo Diesel Performance does it all, whether that be transmission work, maintenance and repair, or performance builds. Their prowess in Duramax and Cummins applications make them one of America's Best Engine Shops!

Duramax Engines have an excellent reputation for reliability. Each model year is associated with problems, especially when the engines reach 100,000+ miles. However, while Cummins engines may continue to edge out Duramax in terms of overall reliability, Duramax fans love their higher horsepower.

These are both relatively common problems you might expect to deal with on the 2001-2004 LB7 Duramax, but you can rest a bit easier knowing the aftermarket has had a decade to develop and perfect the parts you need to correct it.

New models would be zero-emission in 2024, while diesel and gas drayage trucks must retire after 18 years to guarantee that they meet a zero-emission requirement by 2035. In addition, half of all new trucks purchased by state and local governments would be zero-emission in 2024, increasing to 100% by 2027.

Duramax engines are known for their reliability and come standard with a 5-year/60,000-mile limited warranty on 2.8L Turbo-Diesel engines, or a 5-year/100,000-mile limited warranty on 3.0L and 6.6L Turbo-Diesel engines.

Cummins engines deliver more torque than many other trucks on the market, which means more towing and hauling capacity. To construct these engines, Cummins builds the block and head out of iron and uses a steel timing gear, assuring long-term durability.

What is the most reliable Duramax diesel engine? ›

The LBZ also offers excellent tuning and modification potential, which is extremely attractive to most diesel enthusiasts. Finally, the LBZ is the last generation of Duramax without emissions control parts, which gives it superior reliability. For those reasons, the LBZ is our choice for the best Duramax engine.

In terms of performance, both engines have their strengths and weaknesses. PACCAR engines are known for their durability and fuel efficiency, while Cummins engines are known for their power and reliability.

The Cummins engine, which is a popular engine choice for heavy-duty trucks, has by far the finest reputation. Cummins engines are renowned for their dependability and effectiveness. The torque produced by smaller engines was insufficient in the past, but new developments have greatly improved this.

Diesel #2 is typically used by truck drivers across the country. Because diesel is rated by its cetane level, it is important to note that truckers use this type of fuel for a reason. A very important one.

What is this? Specifically, the process consists of replacing the water pump, EGR cooler, external oil cooler, and the fuel injection control module (FICM) with certified Bulletproof Diesel parts. These specific parts help the engine remain cooler and circulate more effectively.

Even with several upgrades throughout the years, there are specific 7.3 Powerstroke years that you probably want to avoid. If you're getting a diesel engine truck, you'll want to avoid the years 1994, 2001, 2002, 2003, and 2004.

The 6.0L fuel injector operates similarly to the 7.3L unit, but the valve that allows high pressure oil to enter the injector body is referred to as a spool valve. Tighter tolerances, and a more technologically advanced injection system, allow the 6.0L Power Stroke to produce higher injection pressures (3,600 psi vs.

The best diesel truck motors are Cummins, Duramax, and Power Stroke, such as the ones below: Chrysler 3.0L EcoDiesel: Generating up to 240 hp and 420 lb-ft of torque, the powerful EcoDiesel has been an option in vehicles such as the Jeep Grand Cherokee and RAM 1500.

In terms of fuel efficiency, Cummins' engines are 6% better than Caterpillar . That's not the only area where CMI's coming out on top. It's taking share from CAT in other heavy-duty engines as well. Cummins is taking share from all its competitors, actually, as it's now the largest supplier to Paccar .

Low-End Torque

Compared to the 5.9, the 6.7 Cummins offers more torque at low RPM. This is thanks to the 6.7's increased stroke: 4.88 inches vs the 5.9 Cummins' 4.72 inches. Trucks with better low-end torque have greater towing capabilities, so this is a clear benefit for the 6.7 Cummins.

What is the longest lasting diesel engine? ›

Like Duramax engines, Cummins engines have a reputation for being long-lasting. So what's high mileage for a Cummins diesel engine? These engines can typically last 300,000 to 350,000 miles, which is considered high mileage –but a well-maintained Cummins engine can reach up to 500,000 miles.

Unnecessary idling wastes fuel, causes air pollution and increases engine wear. An idling diesel engine produces much higher emissions than it would while using the same amount of fuel under load. Extended idling causes a build-up of soot inside the engine and results in a puff of black smoke when the engine revs.

The question on the minds of many this time of year is, “Should I let my diesel engine warm up?” Simply put, yes. In the colder months it's a good idea to let your engine warm up before you hit the road.

The damage begins with the liquids evaporating, leaving behind a thick substance that clogs the engine's moving parts. Ultimately, these parts will stick and begin to deteriorate. If given enough time, the engine will rust and fail to start.

The Cummins produces a low-end torque relative to the Powerstroke, which gives it an edge in towing. Because, with the low-end torque, the engine has an easier time. This makes it more reliable in the long run.

Cummins Brings High-Horsepower QSK95 Engine to Mining Market

Producing up to 4,400 hp, the QSK95 is not only Cummins most powerful engine: it's the most powerful in the ULTRA-class truck category.

Since its inception, the early second-generation Dodge Ram with the 5.9-liter, 12-valve Cummins diesel engine has been iconic. Because of the engine's ability to make cheap horsepower and its super-durable construction, the 1994-1998 trucks will always be highly preferred.

Emissions components is one area where the 7.3L shines, definitively, over the 6.7L—primarily due to its lack of them.

Is Duramax Power Stroke or Cummins better? ›

Both the 6.6L Duramax and 6.7L Power Stroke are V8 engines, with the 6.7L Cummins being an inline six-cylinder diesel engine. Horsepower and torque numbers are similar between the three diesel engines, but the Cummins engine leads the pack with its torque rating breaching the four-figure threshold.

Improve your experience on the road with these tips to keep your truck healthy. It's a common myth that Cummins is owned by auto manufacturers like Ford or Chrysler. In fact, Cummins Turbo Technologies is an independent company that manufactures and markets a complete line of diesel and natural gas-powered engines.

Truckers should use diesel #2 because it's the best option for driving long distances at consistent speeds. Diesel #2 is also less volatile and gives better fuel economy. For those in the construction industry, we offer the best diesel for off-road vehicles.

It sure is! You won't ever sacrifice power for fuel economy ever again because the 2023 Chevy Silverado gets up to 24 mpg in the city and 29 mpg on the highway.

If you're a diesel nut like me, you probably know that most people will steer clear of buying a 2003 to 2007 model year Ford Superduty Diesel truck. The 6.0L Powerstroke is known for having major problems. Most of these problems originate from the factory design.

The new technology, called Ammonia Creation and Conversion Technology (ACCT), works by thermally decomposing NOx using waste exhaust heat further downstream than other after treatment components.

Quick Answer: Avoid Duramax Year Models 2001-2010

The Duramax has a long history. We recommend avoiding any GM vehicle equipped with the 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, and 2010 Duramax engines. In short, the newer model years show improved performance.

Fuel System

Some things to watch out for include problem starting, excessive smoke, lower gear selection, poor fuel economy, a loss of engine power, lower RPMs, and excessive noise. While several possible fuel system problems exist, the 6.6L Duramax consistently has two.

The Duramax valvetrain is more than sufficient at stock and even highly modified power levels. In particular, the rocker shaft system is exceptionally stout. The two forged-steel rocker shaft assemblies incorporate forged-steel rocker arms, each one utilizing a guideless bridge for valve operation.

What is the biggest problem with 6.7 Power Stroke? ›

Injection Pump Failure Leads to Numerous Potential Problems

In the 6.7 diesel engines, the pumps lack adequate lubrication and causes metal to rub against metal. Fragments then make their way into the injection systems and engine. Metal contamination can damage the fuel system, lines, injectors, and regulators.

After years of production, the 6.7L Power Stroke has proven it can storm past the 200,000-mile mark with few repairs. Provided you adhere to Ford's recommended service intervals, there is no reason this engine won't see 300,000 or even 400,000 miles.

Powerstroke Engine Average Life Expectancy:

6.7L200,000-300,000 miles.

What Others Are Reading. With proper maintenance, regular use and EGR system and oil cooler remedies, a 6.0L Power Stroke can be made to blow past the 300,000-mile mark with few, if any issues. The engine might need an injector or two along the way, or an EGR valve, but it can done.

Oil Cooler Problems

Oil must be cooled much more in the Powerstroke engine than in other diesel engines, so Ford equipped the 6.0L diesel engine with an oil cooler that is liquid-on-liquid. Dirt and debris clog the oil cooler which, in turn, causes the EGR cooler to fail, as well.

The 6.0L Power Stroke, was used in Ford Super Duty trucks until the 2007 model year but lasted until 2009 in the Ford Econoline vans (model year 2010) and in the Ford Excursion SUVs until after the 2005 models when Ford discontinued Excursion production.

Biodiesel. Biodiesel is a renewable fuel that can be manufactured from vegetable oils, animal fats, or recycled cooking grease for use in diesel vehicles.

SACRAMENTO, Calif. — The Biden administration cleared the way Friday for California's plan to phase out a wide range of diesel-powered trucks, part of the state's efforts to drastically cut planet-warming emissions and improve air quality in heavy-traffic areas like ports along the coast.

Some manufacturers have already announced plans to ramp up sales of electric truck fleets. Tesla plans to roll out electric semi trucks with 500 miles of range later this year, while Volvo Trucks and Nikola Inc. have launched electric big-rigs and other models with ranges of up to 350 miles.