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Top 5 Mercedes Diesel Engines: Power & Dependability

Mercedes diesel engines are among the most reliable engines seen in Mercedes-Benz automobiles. This automobile manufacturing company has attained a strong market and has attracted a large audience due to its excellent specs and features. They offer luxury vehicles with specific modern features, and their diesel engines increase their worth to an unlimited level. 

Below, I will discuss some top-notch Mercedes diesel engines you can consider before purchasing one.

The top five best Mercedes engines are as follows:

  • OM-606 Mercedes Diesel Engine
  • OM-617 Mercedes Inline-five Diesel Engine
  • OM-603 Mercedes Inline-6 Diesel Engine
  • OM-601 Mercedes Diesel Engine
  • OM-648 Mercedes Diesel Engine

Engine Code Interpretation:

Before I dive into the details of these diesel engines, let’s look at the engine codes delivered by Mercedes-Benz. The engine codes of the vehicles of this company have three components, including the letter with three numbers and another letter at the end.

  • The type of engine can be derived through engine codes, the first letter of which indicates the engine type. The M in the code stands for the petrol engine, while OM indicates it is a diesel engine.
  •  After this, you can detect the family and series of engines through the initial letters. The 2-3 digits after these letters can help you to indicate the family and series of engines. The code number 112 in the M112 example indicates that the engine belongs to a V6 petrol engine.
  •  Similarly, you can detect the engine variants through the last digits of the code. In the example M113K, K will represent the supercharger as a Kompressor.

Let’s discuss these five best diesel engines from the Mercedes automobile company in detail:

1. OM-606 Mercedes Diesel Engine:

Top 5 Mercedes Diesel Engines: Power & Dependability

This diesel engine by Mercedes-Benz has various modern specs and features that have grabbed the attention of its customers in the entire competitive market of automobile engines.

This OM-606 diesel engine was manufactured in 1990, and it swiftly attained a reliable name among its competitors due to its outstanding performance. This diesel engine has a 3.0-litre capacity, a robust design, and is made of cast iron. This structure is a bit heavier than aluminum, seen in almost all types of engines.

Other than this, the built-in features of this diesel Mercedes engine, such as the fuel injection system and turbocharging feature, highly impressed the customers.

This engine can deliver power around 180hp with a torque of around 240lb-ft due to the six cylinders in the engine, which can make it last longer than usual if handled with proper care and maintenance.

2. OM-617 Mercedes Inline-five Diesel Engine:

Top 5 Mercedes Diesel Engines: Power & Dependability

This model of Mercedes diesel engine was manufactured between 1974 and 1991 and was loaded with exceptional features and specs. This engine, named OM-617, has a cast iron body with a 3.0-litre diesel capacity and five cylinders.

This engine gained a quick reputation regarding its reliability factor and became the most stubborn and best diesel engine among its competitors worldwide. Some of the main specs and features of this engine include:

Mercedez Attributes


Name of manufacturers


Year of production

Manufactured in between 1974-1991

The torque offered by the engine


Displacement of engine

Around 3.0-liter

Power delivered by the engine


Type of fuel in the engine


Type of fuel in engine


Despite being highly reliable, the owners of this engine reported some problems, including the timing chain issue and failure of the fuel pump, which are common problems in almost all types of engines. These problems can be handled with proper maintenance and care of the engine.

3. OM-603 Mercedes Inline-6 Diesel Engine:

Top 5 Mercedes Diesel Engines: Power & Dependability

The OM-603 diesel engine is also categorized as Mercedes’s reliable diesel engine. This diesel engine has never failed to provide a rugged and fuel-efficient performance.

This 3-inline OM603 engine was manufactured between 1986 and 1997 and soon attained the position of most reliable engine among its users. This engine has been used in various Mercedes luxury vehicles, including the W-140, W-124, and W-125 series.

Regarding its reliability factor and highest recorded mileage, this engine has covered up to 210,000 miles. Like other engines, this diesel engine has also reported problems, including a broken injector pump or pipe. Such problems can be fixed by seeking help from a mechanic.

4. OM-601 Mercedes Diesel Engine:

Top 5 Mercedes Diesel Engines: Power & Dependability

This diesel engine, OM-601, has fantastic specs and features that help a user operate the engine efficiently with low-emission fuel.

This diesel engine was manufactured between 1980 and soon attained its position as the most reliable engine till the 2000s. This engine has a simple design and has unique attributes of low fuel consumption and emissions.

This is why this diesel engine is quite popular in the category of internal combustion engines. This engine has various notable features, which make it highly reliable among diesel engines. Some of these features are as follows:

  • This OM-601 is a diesel engine which is inline-4cylinder and holds a capacity of 2.3 litres.
  •  This diesel engine is aspirated naturally and is highly durable.
  •  This engine holds the capacity to deliver a power output of about 75hp.
  •  There is the feature of a mechanical governor in it, which is used for controlling the speed of this engine.
  •  This diesel engine has moving parts with a simple design, which increases its reliability.
  •  This diesel engine has a cast iron block with aluminum cylinders, offering thermal efficiency and strength.

If I talk about its reliability factor, this diesel engine owns a cast iron block that can withstand high pressure and temperatures. This engine has timing chains, which ensures longevity but needs special maintenance.

There is also an efficient fuel injection system in this diesel engine, which boosts its reliability and helps reduce air pollution. This diesel engine has been seen in various Mercedes automobiles, including the models W-124, 308D, and T1 van manufactured between 1977 and 1995.

5. OM-648 Mercedes Diesel Engine:

Top 5 Mercedes Diesel Engines: Power & Dependability

This model of Mercedes diesel engine is regarded as one of the most highly reliable and powerful engines among its competitors in the market.

This engine is considered a gem manufactured by Mercedes-Benz, having in-built electronic control features that can optimize the performance and efficiency of the engine.

The fuel injection system of this engine delivers exceptional combustion and precise use of fuel, which is highly regarded by the customers.

Some of the highly notable features of this OM-648 Mercedes Diesel engine are as follows:

  • This engine has six cylinders with 24 valves.
  •  A turbocharger is in it, which is best for boosting the power.
  •  The cast-iron block cylinder helps deliver strength and is thermally efficient.
  •  There is a VNT feature, a variable nozzle turbocharger, which is helpful in precisely controlling the power output from this engine.
  •  There is a fuel injection system that is electronic and helps in the delivery of excellent fuel efficiency. 

Regarding its reliability, this engine can withstand various hard terrains and last longer than usual if handled properly. This engine’s features, power delivery mode, and layout ensure its longevity.

The layout of this engine allows extra room for dissipating heat, which helps repair and maintain the engine. The engine can be well-maintained easily because the components like the hoses and gasket covers are plastic built and are not in direct contact with the iron-cast block. This engine can be seen in various CDI models from 2005 to 2009.

Final Thought:

From robust designs to efficient fuel consumption, these engines have solidified Mercedes-Benz’s reputation for producing some of the finest diesel engines in the automotive industry.

Whether it’s the longevity of the OM-617 or the power delivery of the OM-648, Mercedes diesel engines continue to impress with their innovation and engineering excellence, making them a top choice for discerning drivers worldwide.

Also Read:

7 Most Reliable Mercedes Engines You Can Rely On- Details
5 Reliable Land Rover Engines You Can Surely Count On
7 Most Reliable Audi Engines You Need to Consider

Frequently Asked Questions (FAQs):

Which diesel is considered the best one to be used in the Mercedes vehicle?

The best diesel for the Mercedes is the V-Power Shell diesel. This diesel helps the engine run smoothly and is highly recommended.

Which engine is considered the most reliable one for Mercedes?

The most reliable engine for the Mercedes engine is the OM617 engine. This engine covers around 1000000km of mileage without any specific rebuilding. This is the reason that helped this engine to attain popularity all around the globe and is the powerful one for various automobiles.

Are the engines from Mercedes-Benz considered reliable ones?

Yes, Mercedes-Benz are considered the reliable ones due to their durable mode and ensuring longevity in general. This engine can cover up to thousands of miles if properly cared for and maintained.

It is recommended to keep an eye on the fuel and air filters and frequently keep changing the oil to keep the engine working for a longer duration.

Which fuel type is considered the best one for Mercedes?

The diesel engine is considered the best, and diesel is the best fuel type for Mercedes compared to the petrol option. Mercedes is known to cover up to thousands of miles, so diesel is the best and most cost-saving option for users. Petrol fuel type is best for short trips, having an instant response for throttle bodies.

How long does an average Mercedes diesel engine last?

An average Mercedes diesel engine can last for about 50000 miles in general.

Which C-class Mercedes engine is the best for automobile freaks?

The best C-class Mercedes engine is the C-220 D, which gives lasting pulling power to riders at high speeds. This engine is equipped with a 9-speed automatic mode and is best for keeping the engine in full swing.