5 Of The Most Powerful Diesel Engines Ever Put In Ships

When people think of big engines, they usually think of regular gas engines, like Koenigsegg's 2,300-horsepower monster. However, if you think about it, there are many much bigger vehicles out there, including excavators, locomotives, construction vehicles, and the venerable semi-truck. Most of these work vehicles use diesel engines, and there are several reasons for this. These engines provide high torque, which is needed to operate heavy equipment. The low RPM of heavy equipment also achieves exceptional reliability, with many diesel engines in this category expected to last for decades and millions of miles. Of all the diesel-powered vehicles in the world, ships are by far the largest. 

Big boats need big engines, especially aircraft carriers, which can have crews large enough to warrant comparisons to small cities. For context, the largest engine Cummins has ever made is the QSK95, producing 4,400 horsepower. The RMS Titanic, which sank in 1912, boasted an estimated 46,000 horsepower. Ships are just on a different level than anything you can find on land. 

So, if you want to see the biggest and most powerful diesel engines on Earth, you're going to have to look out to sea, as today's container ships lead the charge when it comes to massive diesel engines. Before that, we'd like to give a quick honorable mention to the WinGD 12X92DF. It generates most of its 85,000 horsepower with liquefied natural gas, but can technically use diesel as a pilot fuel.

Wärtsilä-Sulzer is one of the largest manufacturers of container ship engines and supplies several large industry titans like Maersk. Thus, don't be surprised when we mention them multiple times. For this list, we'll talk about the Wärtsilä-Sulzer RTA84C, a paleolithic ship engine by modern standards, but easily the largest engine in the world back in its day. This massive thing is difficult to find information about, with a few technical manuals floating around online. 

Despite coming out in 1988, this engine was already orders of magnitude stronger than anything on land at that time. We're not sure if it started this way or if it was after a series of upgrades in 1993, but according to the technical documents, the RTA84C appeared to output roughly 70,000 horsepower when completely maxed out. The two-stroke, 12-cylinder engine produced this much power at a remarkably low 102 RPM, as it is a low-RPM diesel engine known for its incredible power output with fewer cylinders running at lower RPM. While it doesn't sound like much, each cylinder is as tall as a building, and container ship engines can be over 50 feet tall. 

It would remain Wärtsilä-Sulzer's most powerful engine for several years and has been outfitted on many container ships. The exact number is known only to Wärtsilä-Sulzer's accounting department, but estimates suggest there are at least 155 container ships worldwide. 

MAN Energy Solutions is another big player in container ship diesel engines, along with Wärtsilä-Sulzer and Win GD. As such, this is the other big name that you'll see on this list. The MAN B&W 11G95ME-C engine is a mainstay of the industry. Revealed to the world in 2015, it was the largest engine that MAN Energy Solution had made at the time. The engine underwent some variations over the years, so this engine technically goes by multiple names. You may see it referred to as the MAN B&W 11G95ME-C or the MAN B&W G95ME-C9.5. They are subtly different but come from the same family. 

In any case, the G95ME engine can produce roughly 103,000 horsepower. That's more than the top 10 Dodge engines ever made combined — times about 10. Like the other ship engines, it's a massive thing, weighing in at 2,230 tons. It is 59 feet tall and nearly twice as long. That's larger than some houses. For specs, it's a 12-cylinder, two-stroke diesel engine that is most often used on container ships. 

This engine is also part of container ship history. It was tapped to power the largest container ship ever built in 2020. After all, a massive ship needs a massive engine, and MAN's engine fits the bill. The ship, known as the HMM Algeciras, launched in 2020 and is still in service. 

If you Google the strongest diesel engine ever made, you'll almost certainly see the Wärtsilä-Sulzer RTA96-C pop up, and rightfully so. At the time of its manufacture, it was the strongest ship engine ever made. It's impressive that it held the title as long as it did. The Wärtsilä-Sulzer RTA96-C came out in 1994, just six years after the company's RTA84C engine, which was still extremely powerful. Over the years, the engine has been updated, but it remains one of the company's most popular.

This engine was truly a marvel in its heyday, outputting a staggering 107,390 horsepower in its final form. What's even more impressive is the torque. It measures at 7,603,850 Nm, which translates to roughly 5,600,000 ft-lb of torque, which is simply an absurd number. Like most large ship diesel engines, it was a two-stroke, 14-cylinder engine in its largest iteration, which was required for it to get its maximum horsepower. Another fun fact to show just how huge these engines are. The displacement of each cylinder on the RTA96-C is 1,820 liters, for a total of 25,000 liters.

As you can imagine, the RTA96-C is equipped on some of the largest ships in shipping container history, including those from some of the largest ships from the biggest shipping companies on Earth. It's a legendary engine with ridiculous amounts of power, but it's not the company's biggest engine. 

A variant of the RTA96-C, known as the Wärtsilä-Sulzer RT-flex96C, is the largest engine made by the Finnish and Swedish duo of Wärtsilä and Sulzer. At the time of its release in 2006, it was the largest diesel engine in the world, and as you can likely surmise from the name, it is often confused with its older, but still very powerful sibling.

At 108,920 horsepower, the two-stroke, 14-cylinder, turbocharged engine is the size of a small apartment complex. In fact, based on the images we found, people have to climb multiple flights of stairs just to get to the top of it. The turbocharger is also rather interesting. The exhaust spins a turbine as it does in a regular car turbo. So much heat comes off the exhaust that a separate system captures it to produce steam, helping to drive the turbine. The RT-flex96C drives the Emma Maersk, which was the largest container ship in the world upon completion. 

The largest engine that takes diesel fuel at least some of the time is the MAN B&W 12G95ME-C10.5-LGIM. It is in the same family as MAN's other engines, just slightly improved. MAN Energy Solution announced this engine in May 2025, so it is the proverbial new kid on the block. The engine was built to power 12 massive cargo ships from shipping companies around the world. Much like its closest competitors, it's the size of a small mansion, and it took a long time to build. 

At its maximum, this engine is rated to produce 82,440kW at 80RPM, which translates to roughly 110,000 horsepower, making it the strongest such engine that we could find. There is a caveat. This engine is designed to use methanol as its primary fuel source, but can use conventional fuels like diesel if the occasion calls for it. MAN doesn't list any horsepower differences based on fuel, so it may be able to output its full horsepower with conventional fuels, or it might not. For specs, it's a 14-cylinder, two-stroke, turbocharged engine just like most of the others in this category. 

Other than using a hybrid selection of fuels, MAN had some other tricks up its sleeve. For example, the engine uses a proprietary turbocharger system that the company describes as the largest two-string exhaust gas recirculation system in the world. The results speak for themselves.