KEY CONSIDERATIONS
- Available for £15,000
- 6.2-litre petrol naturally-aspirated V8 or 6.0-litre twin-turbo V12
- Massive torque from rare S65
- Post-2010 S63s switched from big NA V8 to smaller twin-turbo V8
- Watch out for electrical issues
- Coil packs and spark plugs can be very expensive
OVERVIEW
The 'S' in 'Mercedes S-Class' refers to the German word 'sonder', which means 'special'. That's never been an overstatement for these rolling exhibits of prime automotive engineering, and the W221 S-Class of 2006 was no exception. It marked a return to the 'bigger and better' S-Class tradition that had been interrupted by the preceding W220, bringing focus back onto the traditionally luxurious S-Class feel and extending the scope and integration of the COMAND electronics suite.
For those who wanted more 'sonder' in their S-Class, two AMG versions of the W221 saloon were launched in 2006 - the S63 and the S65. S63 coupes were available too, of course, but for the sake of simplicity we'll be concentrating on the saloons here.
Until 2010 the S63 ran a naturally-aspirated 6.2-litre V8 with 518hp and 465lb ft, which made it the world's most powerful non-turbo V8. It did the 0-62mph in 4.6 seconds and the 0-100 in 12.7. In the 2010 update that engine was replaced by the M157 twin-turbo 5.5-litre V8 producing 536hp and 590lb ft (or, with the optional AMG Performance Package, 563hp and 664lb ft) which, with the MCT 7-speed box, consumed fuel at around three-quarters of the rate of the big boy V8.
New driver assist systems also came along as part of that 2010 facelift, including the latest versions of Night View Assist Plus and Pre-Safe collection protection. That was on top of everything else Mercedes threw (carefully) at its new S-Class, which would fill a small book on its own.
Not everything changed, though, and even that souped-up S63 was no match for the power and torque of the S65 that marched on unchanged through 2010. Its 6.0-litre biturbo V12 produced 603hp and 737lb ft, or more eye-catchingly 1,000Nm, making the S65 the world's most powerful production saloon full stop. The S65 only came in long-wheelbase form and bent the scales at 2,250kg, but despite that, the kind of might it had at its disposal allowed it to operate in a different dimension to just about anything else.
At 1,000rpm the S65 was already churning out 420lb ft. It shrugged off the 0-62mph in 4.4 seconds and blew through 100mph in under 10 seconds, reaching 155mph in just over 20 seconds, at which point it was still turning over at less than 4,500rpm. Now that's motoring. And to think that Mercedes took the torque down from 885lb ft to 737lb ft to give the S65's transmission a chance...
The V12 engine ran serenely on until it finally bowed out with the S65 Final Edition of 2019. In Obsidian Black with bronze wheels and highlights, four of these beasts came to the UK. A couple of them are on sale at the moment to Simon Cowell types for between £290,000 and £300,000.
SPECIFICATION | MERCEDES S63 AMG
Engine: 6,208cc, V8, 32v
Transmission: 7-speed automatic, rear-wheel drive
Power (hp): 518@6,800rpm
Torque (lb ft): 465@5,200rpm
0-62mph: 4.6 secs
Top speed: 155mph
Weight: 2,070kg (LWB model 2,115kg)
MPG: 19.1 (official combined)
CO2: 355g/km
Wheels: 8.5x19 (f), 9.5x19 (r)
Tyres: 255/40 (f), 275/40 (r)
On sale: 2006 - 2013
Price new: £95,000
SPECIFICATION | MERCEDES S65 AMG
Engine: 5,980cc, V12, 36v twin-turbo
Transmission: 7-speed automatic, rear-wheel drive
Power (hp): 604@4,750-5,100rpm
Torque (lb ft): 738@2,000-4,000rpm
0-62mph: 4.4 secs
Top speed: 155mph
Weight: 2,250kg
MPG: 19.1 (official combined)
CO2: 355g/km
Wheels: 8.5x19 (f), 9.5x19 (r)
Tyres: 255/40 (f), 275/40 (r)
On sale: 2006 - 2013
Price new: £145,000
ENGINE & GEARBOX
The M275 bi-turbo V12 of 2002 was Mercedes' response to its own M137 of 1999, a three-valve per cylinder V12 that had a small reputation for oil fouling and cylinder bores going out of round.
Like the M137, the 36-valve M275 had an aluminium block and single-cam heads, but its aluminium crankcase was strengthened with cast-iron inserts. That made it 50kg heavier than the M137, but the total weight of 270kg was still low for such a beast of a motor and the addition of two turbos more than answered the power shortcomings of the older engine. The V12's immense torque allowed it to pull a high-geared five-speed auto with ease, whereas the S63's M156 V8 was hooked up to the usual Merc seven-speeder.
The M275 is tough and generally oil tight but it's not perfect. Electronically, cars like this are very complicated and things do go wrong. Keyless entry and busted inflating seat bolsters can both fritz out. You're well advised to keep the battery in good shape with a trickle charger in order to minimise problems if you're planning on leaving the car for a while.
A misfire (generic fault code P0300) could very well be down to the coils or the ignition module. The V8 has one coil pack per cylinder, so eight in all, and they cost about £60 each. There are only two coil packs on the V12, which doesn't sound so bad until you realise that they're up to £1,000 each. You can save money by having the coil packs refurbished, or the sealed ignition module rebuilt.
If spark plugs are your problem, which can happen with these engines (arcing and insulator damage), changing them on the S65 V12 is a little more involved than the same operation on your Dad's old Austin 7. There are 24 plugs and the official replacement labour time is between four and five hours. The V8 makes do with eight plugs and a 1.5 hour changeover time. Even if you're not having any electronic glitches, the spark plugs should be changed every four years or so.
The bi-turbo V12s anecdotally perform better re the coil packs than earlier V12s, which put extra pressure on them through their fuel-saving cylinder shutdown feature which closed down the left bank under light throttle loads. Having said that, turbo actuator failure is not unknown. If you like to hear a bit of turbo whistle you'll probably like the S65.
Both the V8 and V12 like the odd drink of Mobil 10W-40 so you're well advised to 'check your levels' on a regular basis. There was a recall in 2013 for a potential crack in the fuel filter housing.
The M156 V8 has become known for quite a few issues, which in no particular order include deterioration to the crankcase breather valve diaphragm, and/or cracking of the hose from the crankcase to the breather valve; oil leaks from the valve cover gaskets, camshaft solenoid cover gaskets, and oil filter housing gaskets; camshaft adjuster rattle, usually on the intake side and usually on a cold start; 'soft' camshaft lobe wear at around 100,000 miles, again usually on the intake side; failure of the magnesium alloy intake manifold (guess which side); idler pulley failure; and perhaps most famously of all, stretched/broken cylinder head bolts, usually at the back of the engine, allowing coolant and oil to enter the combustion chamber. In severe cases hydrolock could occur, destroying the engine. Low coolant levels or high oil levels were the obvious giveaways, as was white exhaust smoke from burnt oil.
At one time a rumour was going around that the five-speed transmission on the V12 had to be dropped at around the 40,000-mile mark for inspection and trans fluid change, but in fact it's a quite routine pan removal, filter and gasket replacement and ATF refill job. Gear shifting with the seven-speed gearbox wasn't always smooth, especially on pre-facelift models: electronics again, this time to do with the valve body and conductor plate.
CHASSIS
The S63 originally came in short- or long-wheelbase versions, but after the 2010 update that brought in the twin-turbo 5.5 V8, the SWB version was dropped. The S65 was only ever available as a long-wheelbase car.
Check the car's ride height at each corner. If the Airmatic air bags get leaks, which they can, the suspension pump has to work harder to keep things on an even keel. In the worst case scenario the whole suspension system might collapse.
Both the S63 and S65 had Mercedes' Active Body Control (ABC), a system which was clever enough to detect crosswinds and compensate for them. It wasn't clever enough to turn either car into an Alpine A110 around tight corners, but handling confidence on these beasts does build with speed. The ABC was known for issues in the old W220 S-Class - random vibrations caused by flaky PCBs, fracture of the lower ball joints on the front struts over rough ground - but following recall work early on in its life the W221 was better.
It's sensible to budget around £1,000 a year for tyres, because with such heavy and powerful cars you really don't want to skimp in that area, either in terms of quality or on tread depth and general condition. Standard wheels were staggered 19s with forged 20-inch wheels as an AMG option, using 255/35 tyres up front and 275/30 rears.
When you're checking out a possible car, make sure that the brake pads have plenty of meat on them and that the brake discs aren't lipped - brake repairs on these cars are not your average 'throwing eighty quid at it should do it' job, especially if you go down the original equipment route. Front discs on an S65 can go at around 50,000 miles and that can be a £2,000 job. A warning light for parking brake failure will probably be down to a broken brake switch.
BODYWORK
As a result of the debacle of bodywork problems on turn-of-the-century Mercedes-Benzes, the W221 S-Class benefitted from somewhat better quality control. Even so, corrosion and blistered paint are far from unheard of.
Check for debris in the windscreen scuttle area. If that gets blocked up, water will find its way into the footwells, damaging the air-con unit. Water can get into the boot too. The S-Class's heater blower could stop due to a design fault with the rubber grommet that was used to stop rubbish getting into the motor.
INTERIOR
The interior of an S63 or S65 is a beautiful place, especially because the apparent simplicity conceals such a welter of gizmos and toys. The satnav was a bit rubbish out of the box, the COMAND system refusing to accept more than four keystrokes when inputting UK postcodes, but if you went to the dealer they would sort that out and give you the full seven cyphers.
The cruise-control selector with speed-limiter is wonderfully simple to use. The Distronic option used radar to save you the bother of braking in traffic. Mercedes reckoned it cut the chance of bumping into the back of another vehicle by 75 per cent. Another great option was Night View Assist which used infra-red light and a camera to give you a view three times further up the road than that provided by the headlights. Cunning stuff.
Tall people will love the comfort on offer from the super-adjustable, wide and yet still supportive massage seats with in-built cooling. The sheer thickness of the seats means that the heating elements take a while to make their presence felt, but as soon as they're up to temp the three-mode tush-toastery is second to none. The control modules for the dynamic, massage and heating functions can all give problems, and the same goes for the soft-close door locks.
The interiors are far from gloomy but the panoramic roof is a lovely thing to have (on the LWB cars only), although wind noise could arise from a bust seal.
The ambient cabin lighting had three different colour settings, Solar, Neutral and Polar, and if that was a little bit too successful in creating a smoochy atmosphere there was a drowsiness sensor to stop you slumping over the wheel. There was even a Porsche Sport Chrono-style race timer to record your lap times for all those track days you'd be taking part in (eh?).
Much of the kit in these cars was cutting-edge at the time, but we're not sure that these AMG S-Classes ever had aux sockets. They did however have a slot for an SD or PCMCIA card, so you could chuck all your PC's choons onto one of them and be able to read song info on the screen.
Control modules from locks to seats can be troublesome. Interior door panels can get loose and rattly: M-B eventually released better clips.
VERDICT
The best thing about cars like these, if you're buying in the used market at any rate, is the catastrophic depreciation.
New, the 6.2-litre S63 cost £95,000 before options, and the S65 started at £145,000. One PHer bought a 4,000-mile S65 for £105,000 thinking he'd done well against the car's new-with-options price of £175,000. Eight years later he sold it for £20,000. Gulp. Even so, he was still planning on buying another S65. That's how these magnificent creations get to you.
If you're happy to risk it, you can bathe in the S63 pool for as little £15,000 or luxuriate in an S65 for £25,000, if you can find one. Not many were made. Fewer than a hundred S65s remain on UK roads, with maybe twice that number of S63s (SWB and LWB cars combined).
If you can make sense of Mercedes's Approved Used website you're a better man than us, but it's safe to say that dealer-approved S63s and S65s are thin on the ground nowadays. We'd say give that side of it a miss, look in the classifieds instead and get an expert to bung your preferred candidate on the ramp for a once-over diagnostic at £75 or so. As usual owner forums are your friends here.
Regarding the choice between a standard length S63 or a long-wheelbase version, a 'shortie' will be perfectly adequate for your needs unless all your relatives are pro basketball players. If your heart is set on a V12 but there are no S65s about to buy, there's always the fallback option of a regular S600. They don't make the same noise, but if your V12 interest is based on refinement rather than ruffianism then you may actually prefer the S600. The ride quality is plusher, some maintenance jobs (like the brakes) will be less ruinous to your wallet, and there'll be a wider choice of cars to select from.
Be aware that your initial outlay at any end of the S63/65 market will only be the tip of the AMG ownership iceberg. Floating below the surface is a potentially Titanic-sized lump of running costs. You'll never escape mpg figures beginning with a one (or even worse on the V12), and when the parts geezer reaches for the boxes from the very top shelf of the warehouse you may think you can hear the faint sound of heavenly choirs, especially when he tells you the price, at which point you might wish you were actually dead.
On the plus side, the migration of workshop staff as a result of the notorious M-B UK dealership network clearout a few years ago means that there is no shortage of good independent Mercedes specialists around, whose labour rates will be around half those of a main dealer. If you're doing it the official/expensive way make sure you know exactly what's involved with the servicing schedules and what you'll be paying for. Once you're an S63/65 owner it's well worth looking at joining the AMG Private Lounge website for insights. You can connect up with other owners and get invites to some very nice AMG events, but you can only join with a VIN number.
You can get a snapshot of the expected repair costs on any given car by looking at the price of a manufacturer's 12-month extended warranty. Tier 2 cover on a 2011 S63 AMG L with a mileage in the mid-60k region would be something in the order of £3,000, with a £250 excess. Nothing is cheap in S63/65 Land, but if you can swing it then ownership of one of these magnificent creatures has got to be worth it once in your life.
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