W221 Buying Advice / Buyers Guide

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Active Member
Nov 1, 2013
W221 S320
Hopefully this thread will address a lack of decent W221 advice to a new browser, I'm hoping people will add to or criticise what I post:

I was the second owner of a W221 S320 at about 55k Miles, with a dealer checkup and warranty.

The tyres are lasting about 10,000 a set. 180-240 a tyre based on preferences.

The brake pads and disks need replacement every two years, 600 in specialist, 1200 in merc.

The car need servicing annually, 500/1000 a year basic (merc/spec) or 800/1600 advanced.

I get 26mpg mixed, 36mpg motorway.

My car is looked after but little things break at the rate of 1 per 6mths, £250/500 fix.

I personally would not buy without a merc main dealer assessment

I have NO experience of the advanced equipment available on a W221. I'm hoping several posts follow, including perhaps S500 and S63 thoughts.
This is a god little intro to W221 used ownership!

I have a S350 petrol, 2007 now with 105k.

I've had it for 5 months and have done 6,000 miles in it.

The petrol V6 averages around 25mpg and will get 30-32 on the motorways.

So far the only issue i have had is the usual blockage under the bonnet causing a bit of water to get into the foot well - easy fix, jut whip out the rubber bit - do it before the water comes in if possible thought, I had to pay £600 to get all my A/C repaired in my CL500 the first time it happened.

Brakes and tyres are all still good but they were replaced when I bought the car, and it wa also serviced.

The only issue i have had is the control modules for both the dynamic seats have failed and need to be replaced. MB will charge over £1k for this. However, an indi can do it for a lot less.
I have a 500L with a 118,000 miles.

I bought it new in January 2008, picked it up from the Factory. Well worth the visit.

Since the OEM tyres, I have replaced them with Falken's. I get about 22,000 miles on the Rear's and 18,000 on the Fronts.

Fuel consumption ? On a run 27mpg in town 16mpg, bearing in mind I use it for work and that is 12 to 15 hours of stop start.

It has Full AMG Kit with Exclusive Passion Leather and Alcantara Headlining and 20" AMG's + Distronic Plus and a lot of other goodies.

Up until last year MB Brooklands have serviced it from new and after deciding to keep it Olly at PCS is looking after it. Olly has also looked after the CL since I bought it :thumb:

It's been a very reliable car. Front and Rear Discs lasted 110,000 miles. Had a couple of problems. A starter motor last year and main battery's not lasting as long as they should do. Had the battery module changed a couple of months ago, so we will see if that has sorted it out and a new A/C compressor and drier last summer.

Yes I had that water problem, stupid design :ban:, as you said just throw away the rubber bung :thumb: Had to have a new blower motor.

Very happy, especially with the V8 :D, feels like it's just run in :thumb:
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S500 V8 5.5l


Performance wise it's very good. It's also very quiet, smooth, comfortable, and competent.

Comfort mode seems to set off in 2nd gear, so it does feel a bit weird until you get used to it. Sport mode is very very responsive, but if you're not used to it you may waste a lot of tyre and brake. Manual mode is useless to me - I can't get better economy than Comfort mode, and it's not sportier than Sport mode.

In my opinion the mechanical bits are very reliable, but not the electronics or the gadgets.

The quality of the interior fit and finish is amazing. Once you go S you can never go back.

Very difficult to use on country roads - it's too wide. You are constantly worried about curbing the wheels, especially in city car parks.

On the NTG3 COMAND units, you can only enter the first 4 digits of post code, which is pretty crap to be honest. And because the windscreen is heat-reflective (i.e. it's got silver in the glass), mobile phones don't get a good GPS signal.

The unit is also very picky about the memory card you use.

The windows are double glazed so the car doesn't get super cold in the morning. Heated steering wheel is very nice in winter too! Likewise, ventilated seats are amazing in summer.

Massage seats always make the passenger's jaw drop.

It's very nice to be able to raise the car with a touch of a button when needed.

I like the Distronic Plus very much.

I feel very safe surrounded by airbags.

Running Costs

I get about 22 MPG on average, mixed Comfort/Sport mode, according to the computer.

Insurance is very expensive in general. I got lucky and Admiral somehow is half the price of all the others.

The Bluetooth module needs to be bought separately - it's not built-in.


Tyres are just over £1000 for a full set of Pirelli, but then I have 20" wheels.

When it comes to oil change, it needs 9 litres of oil. So don't buy Castrol, because they come in 4l tubs.

Merc says the transmission fluid needs to be changed at 40k miles, once only. But really it should be changed again at around 80k miles to prevent problems.

Maintenance is expensive but it's expected. Parts are roughly twice the price of a C class I think? Labour charge is also more than others because it takes longer to do the jobs, with it being such a complicated car.

Common problems

- Never let the battery run low. All sorts of problems will come. Have it trickle charged if you're going away.

- Lots of cars have leaks on the air bladders of the dynamic seats. Very expensive to replace, because it comes as one whole unit.

- Lots of cars have dead amplifier, which I suspect is due to water damage. You can see water running down the arm of the boot into the "hole" when you open the bootlid. Again very expensive.

- Many of the control modules can easily die without notice. All of them are expensive.

- Keyless GO door handles die easily. The capacitive sensors don't last forever. And yes, expensive.
Oh yeah, forgot that S350L had to have the amplifier replaced before I picked it up.

I've not experienced any issues with memory cards in the PCMCIA adaptor I bought off Amazon. It has a 16gb card in at the moment and it works fine. However, it does take a while to load up when you first get in the car.
I am looking for my first S class and so very interested in people's real world experiences of costs, reliability and mpg. Please keep posting especially the 320 cdi as this is probably what I will be looking for.

I work for Haymarket who publish Autocar (here's their review) and What Car? (here), and for editorial balance ;) Pistonheads' The Brave Pill here but this forum is really good for more info so take some time to read around, and you'll get a good idea of what's in store.
Well the W221 350 has the better engine,there are quiet a few for sale,what to look for is a big spec one,there are plenty of poverty ones out there,what I would consider essential is memory front seats,this gives you the near side door mirror will dip down so you can see the rear wheel when reverse is selected,a rear camera,heated front and rear seats,if you go for a long wheel base you get the sun roof as standard,if you look at the photo's in the adverts look at the light switch to the right of the steering wheel there are places for two switches on the left are headlamp washers and on the right night view assist, these are nice to have,full MB service essential,and ATF change no matter what the mileage as you are looking at least a 8 year old car,having said that there is a 2007 320 on ebay in red that has a good spec and very low mileage,and it is at the right money.

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