The Mercedes S-Class is a flagship full-size sedan from Mercedes that aims to satisfy those who want the most luxurious limousine that is equally impressive to drive and to be driven in. The S-Class first began back in 1972 with the W116 generation and the latest one is the W223 which came out last year.
The S550 S-Class variant is a higher spec model that comes with an 8-cylinder engine and the first S550 was introduced for the 2007 model year, the W221. The second generation of the S550 was introduced in 2014 under the W222 model designation. The current W223 is not being offered in an S550 variant.
The first-gen 2007 S550 offers a 4.7L V8 which is relatively reliable, but the W221 S550 is known for having auxiliary battery issues, air suspension issues, and transmission electronics issues. The second-gen W222 S550 is mostly known for potential electrical issues and issues with the steering system.
All in all, the S550 is a relatively reliable S-Class variant, but it does cost a lot of money to maintain as it comes with all sorts of complex technologies and features. If you are in the market for an S550, both the first and the second generations are decent in their facelifted form.
Auxilary battery issues – W221
The W221 S-Class comes with 2 batteries. The first one is used to power up the engine while the other is used to power all the interior electronics including the transmission. Mercedes decided to do this so you can put your car in park even when the main battery dies, but the issue arises if your auxiliary battery dies first.
This is a fairly common problem for the W221, yet it can easily be resolved by simply replacing the battery in due time. Most mechanics suggest that you should replace the battery every 100,000 miles or 7 years which means that this is more or less a once-in-a-lifetime task. Replacing the battery is also relatively easy because it is situated behind the rear seats.
Air suspension issues – W221
The W221 S550s is equipped with a clever Mercedes AIRMATIC air suspension that offers an incredibly comfortable ride, but it is sometimes prone to cause issues, especially if not maintained correctly. The air compressor is known to fail after a while which results in the suspension not generating enough pressure to raise the car up.
Another potential issue with the air suspension found on the W221 is the air suspension airbag that is also known to fail after 100,000 miles or so. The AIRMATIC found on the W221 is a lot better than the system found on the W220, but you need to maintain it if you want it to perform adequately at all times.
Transmission electronics issues – W221
The pre-facelift W221 is generally not as reliable as the post-facelift version and the 722.9 7-speed automatic gearbox is a perfect example. The pre-facelift W221 used a faulty transmission control unit which was known to fail and so did the conductor plate and the control unit.
This problem usually results in the car being placed in a limp mode which means that the car is able to drive up to speeds of a few miles per hour.
Electrical issues – W222
The W222 S-Class is considered to be one of the best S-Class models of all time and it still looks and feels brand-new, especially the post-facelift model. However, no car is without fault and it’s the very same story for the W222.
The W222 S550 is known to flash various warning lights on the dashboard due to worn-out sensors which are rarely ever due to a legitimate problem. The W222 is an extremely complex car and issues such as these are relatively common.
Steering system issues – W222
The steering system on the W222 is known to be reliable for the most part, but when it starts causing issues, those issues could be fairly problematic. A few owners complained that their W222 S550 makes grinding noises while steering and the issues were later pinpointed to the steering coupling and the rubber bellows.
Power-assisted steering is also known to sometimes cause issues and the car is likely going to flash a warning light on the dashboard if that is truly the case.
Is the W222 S-Class better than the W221 S-Class?
The W222 S-Class is indeed better than the W221 because it introduced the S-Class into the future by incorporating a double-widescreen dashboard design that is now common even on entry-level Mercedes models. The W222 S-Class truly did set the standards for all the other Mercedes models down the food chain.
The W221 is also a great car, especially the post-facelift version, but it simply can’t match the W222 for luxury, comfort, technology, or overall design appeal and desirability.
Is the S550 the best Mercedes S-Class variant?
The S550 is classed as a higher mid-level S-Class model that perfectly balances performance, comfort, and maintenance costs. The S600 V12 model is indeed smoother and more desirable, but it does cost a lot more money to run and maintain. It uses more fuel and it is more expensive.
The S500 model and lower are indeed true S-Class models but they offer smaller engines that are not nearly as punchy as the engine found in the S550. As such, the S550 might as well be the best S-Class model you can buy.
Is the S-Class a benchmark full-size luxury sedan?
The German luxury trio Mercedes, BMW, and Audi continue competing for the best product in each and every segment out there. The full-size sedan segment is characterized by the S-Class, but Audi does make the lovely A8 and BMW makes the equally lovely BMW 7-Series.
These are able to trade punches for days, but the W223 S-Class is the newest car of the bunch and is currently the best one of the trio. The S-Class indeed tends to set standards for the full-size luxury sedan segment and that is rather obvious because Audi and BMW are always trying to catch up when it comes to sales.