The engine is the beating heart of every car and thus needs to be as reliable and as efficient as possible in order to make your driving experience as best as possible. Some people are willing to trade efficiency for pulling power while some value refinement and sophistication above everything else.
Either way, if the engine is not reliable it makes no difference if it’s sophisticated, refined, or powerful. Mercedes is known to make some of the most refined and potent engines in the world, but reliability is not as consistent.
There are a couple of extremely reliable Mercedes engines such as the 2.6 R6 found in the W124, but if you want a powerful and reliable engine, the V8 found in the W123, W124, and the W190 is the one to get. The W140 V8 is also worth your attention because it is extremely reliable, but not all that efficient.
The V6 found in the W211 is also a fairly reliable engine and so is the 2.0d found in the W123, W124, and the W190. If you want a potent legendary diesel Mercedes engine, the 3.0d found in the W124 is the one for you.
Mercedes 2.6 R6 (W124) engine
If you want to find the most reliable Mercedes engines in existence, all you need to do is ask a senior taxi driver, and the R6 is arguably the most reliable engine of the bunch. Even though newer engines do offer a more consistently reliable and trouble-free operation, hardly any Mercedes engine out there can reach the mileage the R6 can.
The in-line 2.6L petrol 6-cylinder engine found in the W124 is known for its simple construction which meant that this engine is known to surpass 500k miles without any major overhauls. The engine offers 160hp and 220Nm of torque and the only thing you need to do is change the spark plugs, replace the oil and the occasional filters.
Mercedes 2.0 V8 (W123, W124, W190)
Even though the R6 engine is reliable, it is not all that efficient. However, if you want to combine both efficiency and reliability, the 2.0 V8 found in the W123, W124, and the W190 is the one. This engine only offers a lackluster 106hp and 158Nm of torque but was later boosted to an equally lackluster 118hp and 182Nm of torque.
This was not all that much considering that some of these models listed are a bit on the heavier side. Even so, no one could complain about reliability and efficiency. The 2.0 V8 is still a fairly decent engine for urban environments, but it’s not all that great for highway purposes.
Mercedes 4.2 V8 (W140)
The 1980s were the golden time for Mercedes because most engines and their corresponding cars from that era were indestructible. After all, the main priority was reliability. Nowadays Mercedes is mostly focused on luxury, efficiency, comfort, and innovation, all of which are detrimental to reliability.
The 4.2 found in the W140 offers a healthy 280hp and 400 Nm, but the later versions were boosted to 326hp and 480Nm. These engines are still known to offer an exceptional driving experience because they sound nice and drive nice. However, they were never meant to be economical.
Mercedes 3.5 V6 (W211)
The W211 E-Class is one of the most successful Mercedes Benz models of all time because it offers a perfect balance between a modern-day luxury/efficiency Mercedes philosophy and the good old Mercedes built to last philosophy.
Most engines from this era were questionable, except for the 3.5L V6. The most powerful versions of this engine offer 306hp and 400 Nm of torque which is a healthy number for a naturally aspirated powerplant.
Mercedes 2.0d (W123, W124, W190)
It’s only right to include diesel in this list as well because the 2.0 diesel engine found in the W123, W124, and the W190 is an icon. This 2.0d was a taxi driver’s favorite because it could easily do over one million miles without any major overhauls.
However, this engine only offers a pitiful 75hp and 126 Nm of torque which is a number almost unthinkable for the modern era.
Mercedes 3.0d (W124)
To finish off the list of most reliable Mercedes engines of all time, we have to talk about the 3.0 diesel found in the W124. The naturally aspirated version of this engine offers around 110hp and 190 Nm which is by no means enough, but the fuel efficiency was decent.
You could also step up to the 3.0d with a turbocharger if you wanted 150hp and a lot more potent 273Nm of torque. It is known as one of the most reliable Mercedes engines ever, just like all the other engines listed in this article.
FAQ Section
Are modern-day Mercedes engines as reliable as older ones?
Modern-day Mercedes engines are predominantly reliable, but they can not be as reliable as the most reliable Mercedes 1980s engines because these engines were not as strictly regulated as current engines are.
Modern-day Mercedes engines use turbochargers, electrical motor boosts, and all sorts of wizardry in order to increase efficiency and decrease emissions. As such, these are likely not going to be able to last as long.
What is the best Mercedes engine of all time?
The best Mercedes engine of all time is the 6.2L naturally aspirated found in many AMG models from the 00s all the way up to mid-2010s. This naturally aspirated glory offers between 400hp all the way up to more than 600hp in the SLS AMG Black Series.
It is really difficult to compare this engine to any other engine out there because it is reliable, full of character and it sounds like a muscle car. Easily one of the best engines of all time.
Why are engines becoming smaller?
Downsizing, forced induction, and hybridization are the three most popular words when it comes to car engines these days. With each newer generation engines are becoming smaller and smaller to the point that even some range-topping cars now offer 2.0l 4-cylinder engines which were unthinkable a few years back.
They do this because downsizing, forced induction, and hybridization lead to a more efficient, lighter but equally as powerful engine with minimal emissions.
