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Although often slated by some, and constantly criticized thanks to the emissions kicked out, diesel engines serve a valuable purpose in the automotive world. It wasn’t long ago that the public were being encouraged to buy diesel cars and trucks, as they can typically be more fuel efficient than gas engines, although the narrative seems to have changed since.

Still, many continue to love them due to their excellent abilities for towing and hauling, and specifically big-capacity engines for this purpose, with plenty of torque on tap. So, to establish what some of the best diesel engines ever made are, we’ve gathered together ten hugely powerful and monstrously torquey diesel engines from various automakers, and ranked them in order, using their impressive torque figures.

10 Toyota: 3.3L V6 Turbo Diesel

Peak Torque: 516 lb-ft

It would be rude to compile a list of the best diesel engines ever, and to exclude any efforts by Toyota. Unfortunately, this particular engine is reserved for the 300-Series of the Land Cruiser, which isn’t offered to Americans, although it is an impressive lump all the same.

Power comes in the form of 304 rampant horses, while torque is a respectable 516 lb-ft – a figure that sees the Land Cruiser capable of towing 7,700 lbs. By way of comparison, the 250-Series Land Cruiser offered in the States is powered by a 2.4-liter gas-hybrid powertrain, which develops 326 horsepower, but less torque, at 465 lb-ft.

9 Audi: 3.0L V6 Turbo Diesel

Peak Torque: 516 lb-ft

Unusually, when Audi looked to launch a new ‘S’ variant of the executive A6, they turned away from the slew of powerful gas engines on offer, and instead opted to fit a high-torque diesel engine. If that doesn’t sound right, it’s because the diesel option was only available in Europe, while a more powerful gas V6 was sold in America.

While lacking over 100 horsepower in comparison to the gas-powered C8 S6, the benefit of the diesel is increased fuel economy. That’s perfect for long commutes and dull highway drives, although with 339 horsepower on tap, the diesel sedan still managed to provide an enjoyable driving experience.

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8 Ford: 7.3L V8 Power Stroke Turbo Diesel

Peak Torque: 525 lb-ft

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Powerful diesel engines are nothing new, not for trucks at least, as is evidenced with this 7.3-liter turbo diesel V8 from Ford. Used for the Super Duty range between 1994 and 2003, this early Power Stroke engine pushed out 450 lb-ft of torque – ample for a workhorse in that era, although a number easily dwarfed in 2024. Later models were blessed with updates, bringing that output to a more meaningful 525 lb-ft. Alongside Super Duty applications, commercial trucks and the E-Series Ford also made use of this engine.

7 Mercedes-Benz: 3.0L I6 Turbo Diesel

Peak Torque: 553 lb-ft

Mercedes-Benz is a brand that has long been associated with truly great diesel engines. The diesel offerings from Mercedes haven’t always necessarily been powerful, but they are world-renowned for being some of the best and most reliable diesel engines ever built, with many examples having clocked in excess of a million miles.

Now, not to say that the OM656 engine isn’t reliable, but it certainly does put power as its main priority, with 308 horsepower and 479 lb-ft on offer in less powerful models, and up to 362 hp and 553 lb-ft in others. That’s enough to make this the most powerful diesel engine ever offered by the automaker, for passenger cars at least, and it can be found under the hood of many premium SUV models.

Discussion

Diesel vs gas: Do diesel engines have an advantage over gasoline?

Diesel engines typically produce more torque and superior fuel economy compared to a gasoline engine. They can typically tow more too. They do usually have less horsepower and diesel is more expensive to purchase. Would you buy a diesel-powered car?

6 BMW: 3.0L I6 Quad-Turbo Diesel

Peak Torque: 561 lb-ft

While only packing half the cylinders of another Audi diesel on this list, BMW was keen to join the hilariously powerful diesel SUV party, and so offered its M50d engine in the X5, X6 and X7, among others. Once again, though, American shores were denied the privilege of this powerful diesel engine.

In an effort to ensure the diesel inline-six was worthy of the ‘M’ designation, no fewer than four turbochargers were strapped to the ‘six’, providing a peak of 395 horses, alongside 561 lb-ft of torque. This made it the most powerful, and therefore best, diesel engine ever produced by the Bavarian brand.

5 Volkswagen: 5.0L V10 R50 Turbo Diesel

Peak Torque: 627 lb-ft

Once again, the Germans were keen to indulge their crazy side during the 2000s, and while Audi had drawn the wild card and produced a diesel-powered V12, Volkswagen instead had to settle for the reserved option of crafting a V10. While the Q7 had always been considered a luxurious product, the Touareg for which this 5.0-liter V10 was always destined had always been a cheaper, less prestigious product, which made the combination all that more exciting.

The V10 engine was available in two outputs; one with 553 lb-ft of torque and 309 horsepower, while the desirable R50 trim boasted an altogether more meaningful 627 lb-ft of torque, alongside 345 horsepower. Absolute lunacy, and this time, Americans were allowed to join in with the fun.

4 Audi: 6.0L V12 TDI CR

Peak Torque: 738 lb-ft

Despite the fact that Audi might be heavily associated with electric crossovers, and executive sedans right now, wind the clock back 15 years, and the four-ringed brand was tackling some far more interesting projects.

Considered a ‘last hurrah’ before environmentalism really took hold, Audi crammed a ludicrous 6.0-liter V12 engine under the hood of its flagship SUV, the luxurious Q7. Torque was huge, at 738 lb-ft, but it was powerful too, with 493 horses at the driver’s disposal. To this day, it is the only diesel-powered V12 engine to have reached production in a passenger car. Sadly, the V12 engine was offered in Europe only.

3 GM: 6.6L V8 Duramax Turbo Diesel

Peak Torque: 975 lb-ft

If you spot a GM truck adorned with the Duramax badge on the hood, just know that it’s a mightily capable pickup, with one of the best diesel truck engines on the market right now. The 975 lb-ft on offer ensures that the more capable Chevy Silverado and GMC Sierra HD trucks can tow and haul impressive amounts, with peak torque arriving at just 1,600 rpm. That’s right where you need the grunt when fully loaded up, and so it’s no surprise that these diesel-powered trucks are some of the best-selling models in their segment right now.

2 High-Output Cummins 6.7L I6 Turbo Diesel

Peak Torque: 1,075 lb-ft

If you go out and ask, ‘what is the best diesel engine for a pickup truck?’, the chances are the answer you get back will be a Cummins of some sort. Cummins diesel engines are renowned for being hard-workers and mightily powerful, and this High Output 6.7-liter inline-six is thankfully no exception to those rules. Narrowly out-performing the standard output variant of Ford’s latest Power Stroke engine, 1,075 lb-ft of torque is supplied to the largest and most capable of Ram’s pickup truck range. The 2024 Ram 3500 HD can tow an impressive 37,090 lbs when properly equipped, and with this Cummins mill under the hood.

1 Ford: High-Output 6.7L V8 Power Stroke Turbo Diesel

Peak Torque: 1,200 lb-ft

A torquey diesel engine is great for towing and hauling heavy loads, which is a well-known logic, and has been for some time. While many pickup trucks churn out in the region of 400 to 500 lb-ft of torque, the Super Duty line from Ford prefers to offer around double these figures, which is why they are so popular as tough workhorses. However, someone at Ford decided that 1,050 lb-ft of torque from the Power Stroke V8 just wasn’t enough, and so a High Output variant was introduced, boosting that figure to a ‘chassis-twisting’ 1,200 lb-ft. That’s an insane figure from a production vehicle, and enough to see the 2025 Ford Super Duty trucks towing up to 40,000 lbs while still staying within allowed capacities. That’s why this is one of the best diesel truck engines ever produced.

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​​​Sources: Ford, Ram, GM, Toyota, Audi, Mercedes-Benz, Volkswagen, BMW