I am back again after spending too long trawling through our used car listings trying to find prestigious badges at the bottom of their depreciation curve. There are still no £20,000 Ferraris or Lamborghinis I can find, but this week’s choice has plenty of performance and peril.
Last week, it was the turn of the Italian tyre smoke machine, the Alfa Romeo 147 GTA, with its beautiful V6 and no smart way of getting its power down. This week it’s time to up the performance even further, up the cylinders and go for something equally left field.
The BMW M6 was a £85,000, 500hp sports coupe introduced in 2005 and quietly discontinued in 2010. It was monstrously fast, monstrously complicated and its 5.0-litre S90 V10 has developed a reputation for going very wrong. Nowadays, a leggy M6 can be found for less than a five-year-old BMW 3 Series. Would you?
From £15,000
They’re quickly on the road to being collector’s cars, as every M5 before has become. With well-documented reliability issues from the fiendishly demanding and difficult to work on M5, a full service history and deep pockets are the way to go if you want to experience the performance.
The BMW M6 of the same era doesn’t have the same fanfare surrounding it, which makes it a potential hidden gem in the M car back catalogue. The M6 (E63) shared the same troublesome V10 with the M5 but wrapped up in an odd-looking coupe body.
It’s also a little lighter than an M5, thanks in part to a carbon fibre roof, and it’s also quite a bit rarer – only 650 are believed to have been officially sold in the UK. The 0–62mph time is slightly quicker and there was even a convertible model (the E64) for enjoying the full orchestral might of the V10 engine.
It’s more of a grand tourer than sport car – very refined and quiet for long distances, but with keen handling and startling performance when pushed. It was softer and heavier than its sportier rivals, but it could still hang in the bends.
The M6 launched in 2005, which meant it was immediately pitted against the then all-new Aston Martin Vantage, a car that’s guaranteed to receive the WCPGW treatment sooner rather than later. The Aston is far more of a sports car, has a more desirable badge and its V8 engine both sounds excellent and is, if anything, more reliable than the M6.
Or there’s the Porsche 911, the de facto sports car of any era since 1964. The M6 squared off with the 997-generation 911 which launched in 2004 and proved to be a much better sports car. It sold far better than the M6 and again, reliability records are more positive.
Both the Aston Martin and Porsche command more money on the used market too. Both start at around £25,000 for a tired example, more than double the cheapest M6s I’ve come across. A Porsche 911 with similar power to the M6 (like the all-wheel-drive 911 Turbo and its 473hp) will command north of £30,000 for a reasonable one.
Parts supply is good for the ageing M6, good news, as this engine is infamously flaky. A servicing kit with engine oil, air filter, cabin filter and 10 spark plugs is a hefty £451.14, but in plentiful supply. Front brake discs (direct from BMW) are £371.54 a pair, while a new left headlight unit is £861.07. The good news is that most items are in good supply, even down to trim pieces and body panels – even if they are eye-wateringly expensive.
BMW doesn’t make a 6 Series anymore, the closest thing to a modern M6 is the current BMW M4. The two share more in common than you may think; the M4 is slightly more powerful at 530hp, weighs about the same (1770kg), and is just as stylistically challenged. An M4 accelerates quicker than an M6 but also starts at £91,415, serving to make an M6 look even better value for money.
To find out more, read our full BMW M6 (2005-2010) review
Pros
- Thunderous performance
- Excellent engine (when it works)
- Convertible option
Cons
- Very expensive to run
- Very complicated electronics
Common issues
Looking to buy a used BMW M6? Here’s what we’d look for.
- Engine rod bearings – That V10 isn’t for the fainthearted, the rod bearings can wear, causing an engine knock and even total engine failure if not resolved. Budget at least £2,000 to correct.
- Throttle – The throttle actuator can fail, causing the car to enter limp home mode and a rough idle. They’ll need replacing and it’s easily £500 per actuator
- Transmission – All M6s sold in the UK use a sequential manual gearbox (SMG) that can develop jerky shifting and even fail to engage. This can be down to worn sensors or the hydraulic pump failing. It’s a big bill to mend.
- Cooling – the oil cooler can degrade on high mileage examples and will need replacing. The coolant expansion tank is known to crack, while radiators leak with age
- Oil – It’s a popular joke that BMWs need a lot of engine oil, but this engine needs 9 litres of the stuff (premium naturally) and oil leaks are a common occurrence.
Should you buy a BMW M6?
That’s a tricky question to answer, simply because the BMW M5 of the same era is equally affordable but makes for a more useful and popular choice. The M6 is less practical, not that much better to drive and just as prone to breaking down. It does have rarity in its corner, but there’s something more appealing about having that engine in an uber-fast saloon or estate. Values form M5s will probably go up too in the future, not so much for the M6.
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