Mercedes S Class W221, a car that’s still relevant even 8 years after it ended production. Has Mercedes learned anything and made the Mercedes S Class W221 another worthy chapter in the history of it’s flagship?

Every time a new episode of “Jersey Shore” is announced, the whole world goes wild. That’s how the automotive world feels when the next S Class is announced. People are always wondering “what will they come up with next?” and the Mercedes S Class W221 almost came with the same wheelbarrow of world firsts. I say almost because a lot of technology debuted on the W220 and some even on the W140, but the technology on the W221 remains relevant even today, 8 years after production ended and it will still remain relevant for millenia to come. Radar guided adaptive cruise control, massage seats, fatigue sensors, lane assist, and all the crazy stuff. Sure, not very impressive in 2023 when you can find some of this stuff on a Kia Picanto, but for 2006 this was quite a feat.


As a successor, the Mercedes S Class W221 made a conceptual swap with the W220. If the W220 was a bad car but with excellent engines, the W221 is an excellent car but with bad engines. It was probably too much effort to make an excellent car with good engines, but most likely the reason is that we are still in the dark ages of reliability for Mercedes. In fact, it’s so dark it makes Idris Elba look like Ed Sheeran in comparison.


Mercedes S Class W221 Engines


  • 3.0 V6 of 231 horsepower  – Normally this engine was exclusive to UK, Ireland, and Asia, but since there are so many RHD S Classes running around Europe, I feel compelled to include this engine. As for the engine, we talk about it separately in the column for the M272.
  • 3.5 V6 of 272 and 306 horsepower – Until 2010 we have the same issue-ridden M272, and after 2010 comes the M276 which was a much better engine but not free of issues any more than soccer matches are free of brawls.
  • 4.7 V8 of 340 horsepower – You get 2 extra cylinders so increased power and reliability. However, we’re not there yet with reliability so we still need to get a little more out of this M273.
  • 4.7 V8 Bi-Turbo of 435 horsepower  – Same V8 but with two turbos and much higher reliability. The only notable concern here is that the early units had over-capacity injectors and ended up spraying petrol all over the engine. Fortunately, any M278 engine in 20-20 should have this issue solved and be one of the most reliable engines on the market, regardless of size.
  • 5.4 V8 of 388 horsepower  – Top of the line for the M273 but to be honest I too would like to retire with a displacement of 5461 cubic centimeters and 8 cylinders mounted in a V. Mmhmm….
  • 5.4 V8 Bi-Turbo of 544 horsepower – What’s going on in Germany that they’re jumping straight to 2 turbos? In any case, besides the classic timing chain issue, the M157 engine also has situations with the engine mounts and the fact that the turbos are very close to the cylinders so the lucky ones are cylinders 1 and 5 which will have a short life.
  • 5.5 V12 Bi-Turbo of 517 horsepower – The same 5.5 V12 taken straight from the W220 and put to work on the W221 in the form of the S600, now with 7 more horses and 30 Nm of torque up to 830. Occasional issues with the coil packs, but we’re already too far gone in the automotive stratosphere to ask about reliability and maintenance costs.
  • 6.0 V12 Bi-Turbo of 612-horsepower  – The same M257 remains unchanged under the hood of the S65 AMG, Maybach, and the rest of the exotic craze. So exotic, that if it were a person, Trump would have built a wall around it.
  • 6.2 V8 525-horsepower – Notorious especially in the C63 AMG, E63 AMG, or SLS, this engine has long been AMG’s workhorse. A sort of village bike but built entirely from virgin leather, diamonds, and Tom Jones cassettes, this engine is very well documented so you can find out immediately what’s wrong with it. Between oil incontinence, intake manifold, accessory belt, and hydraulic lifters, you’re spoilt for choice.


  • 2.2 l-4 of 204 horsepower  – In 2010 the blasphemy known as the S250 cdi appears, using the same 2.2 cdi from the C Class, E Class, Sprinter, Vito, Citan, Logan, ML, GLK, Graham Norton’s live set, and so on. Unfortunately, the 250cdi version comes with the classic injector issues that I talked about in the E-Class article.
  • 3.0 V6 of 235-horsepower  – Famous for the “Black Death”, the most popular engine in the Mercedes S Class W221 doesn’t really like the city at all. It clogs the intake manifold, the swirl flaps get stuck from dirt, the injector seals crack, the whole engine gets contaminated, and so on. If you’re going to go extra urban with it, it’s perfect. If you’re going to drive it from home to the casino and back and charge a protection fee, then be careful with this engine. As for the black death, it’s because the oil cooler is seated deep inside the V. The seals wear out prematurely and if you ignore it long enough, your engine will seize, in a pool/sludge of oil. The seals or even the oil cooler are not expensive, but the labor will kick you in the nads.
  • 4.0 V8 Bi-Turbo of 320 horsepower  – Because no one bought it anyway, and of the few who actually bought one was happy, the OM629 engine was also taken out of the W220 and moved to the W221, just like a cowroker on the night shift who’s been asleep in his chair for hours and you have to wake him up to tell him to move somewhere else. Ah yes, the automatic transmission still can’t cope with the torque of this engine.



  • 3.5 V6 petrol + electric 299 of horsepower – Apart from the tax exemptions, I don’t see why you’d buy an S400 HYBRID. The Germans probably don’t see why you’d buy one either, but it’s important to have a few hybrids available to keep model-level emissions averages as low as possible.
  • 3.0 V6 diesel + 265 electric of horsepower – Can I copy-paste from above, only instead of S400 Hybrid write S300 BlueTec Hybrid? May I?


Mercedes S Class W211 General Issues

  • It’s good that at least the car is reliable, I’m tired of writing about engines. The main issue is that it has so many electronics that you have to get used to the idea that absolutely every button and every function will never work at the same time. Plus there will probably be functions you won’t even know about.
  • It’s a Mercedes S Class so everything from spare parts to mundane maintainance will be given to you and your account at a premium price. To put things in perspective, I know a gentleman with a W221. One day the windscreen cracked from a stone. The windshield cost 1500 euros to replace, but his concern wasn’t that 1500 euros. His concern was that a new windscreen will never be mounted as well as the factory one, so it will have a shorter lifespan.
  • For V6 petrol engines, code name M272 there are issues with timing chain tensioners and camshafts. With the timing chains, you can fix it somehow, but when it comes to replacing the camshaft you have to take the whole engine out and it will cost so much that you can buy a W220 in good condition. Same with the petrol M273 V8, but less often.
  • The 7G-Tronic gearbox is present on all engines except the 6.2 V8 petrol. I really don’t have room to write about this gearbox, as some people say it’s the worst dog food, and other people say it’s fine. If you’re not a fan, you won’t like it. If you’re a fan, you’ll defend this box to the death.
  • The Airmatic air suspension also comes back on the Mercedes S Class W221 (you’re not going to install coilovers on an S Class, although probably somewhere in Eastern Europe there are some W221s on coilovers) although it’s much sturdier than the one on the W220 and much cheaper to fix.


Mercedes S Class W221 Verdict

But that hasn’t stopped people from buying a W221, on the contrary. Like the BMW E60, the W221 has attracted businessmen, multinational executives as well as people who have chosen other paths in life to make ends meet. Except, unlike the ML where you usually find the executioner, the kind of mobster who transports his bottom in a Mercedes S Class W221 is much more dangerous and plays to a much bigger table. The generous boot holds at least 4 victims, 8 even if you put them in bodybags. But only if you have the version without a fridge in the boot, as that eats up too much space.


What engines do you recommend? For petrol, I recommend the 3.5 V6 petrol with 306 horsepower after 2010, and for diesel anything I recommend, all 3.0 diesel and 235 horsepower you’ll buy. And if money doesn’t mean anything to you, then the 612-horsepower 6.0 V12 Bi-Turbo is the only option.