An insider's view: the hottest Mercedes tuner in the world

AMG, Mercedes-Benz's in-house tuning company, is one of the most revered in the industry. For a start, it makes some of the most powerful production cars on the planet, but step into its world and you realise that it's not just about huge power outputs - it's so much more than that. We were lucky enough to get a guided tour around the German HQ of one of the world's foremost performance fettlers.

One man, one engine

That's the phrase that defines AMG. 'One man, one engine' is the principle that every one of AMG's engines is hand constructed by just one person, who then puts his signature on an engraved plaque on the engine cover. Buyers can even - if they like - meet that person and some have flown to Germany just to do so.

The AMG factory is far brighter than the oily, dirty workshop you might expect it to be; in fact, it's more like the type of place you'd conduct open-heart surgery in. Rows of bright metal shelves filled with neat plastic trays stretch from one end of the room to the other, with the aisles separating them lined by overhead pneumatic tools. Each of the 60-strong team of highly trained AMG engine builders takes a wheeled cart and a bottle of oil and sets about down each aisle, picking up parts like an engine supermarket and putting them together.

Depending on which engine is being built, the process takes three to six hours. AMG claims this method makes its engines far more consistent - with only 3bhp power variance between each, compared to up to 30bhp for a machine-built unit. That's astonishing considering that the 6.2-litre V8 of the E 63 AMG has 517bhp and the 7.3-litre V12 the company produces for the Pagani Zonda supercar has 543bhp.

Unbreakable

With its engines putting out such astonishing power figures, and with 20,000 of them produced every year (which sounds a lot from just 60 men, but it's possible - you do the math), they need to be durable. Therefore, each goes through hundreds of hours of high-speed testing. AMG took us into a dark viewing room and there, behind two inches of bulletproof glass, was the 6.2-litre 571bhp engine from the upcoming SLS 'swing wing' supercar (set for 2010 at around £155,000) being revved to within an inch of its pistons to make sure it can cope with the rigours of everyday high-performance driving. On the test bed, an engine can be tested for the equivalent of 800 hours driving in just three days - causing the entire exhaust system to glow bright orange. None have exploded, yet.

And, possibly to reduce the guilt of its engines producing so much CO₂, each of the nine engine testing beds is linked to a dynamo that converts the energy generated into electrical power - enough for the entire AMG factory in fact.

Each to their own

As you'll imagine, some AMG buyers are among the wealthiest people in the world, and when money's no object, sometimes driving something that 'anyone' could have just won't do. So, AMG took us into a dark warehouse adjacent to the engine testing facility where there is a handful of very special cars. One of the cars there, an ML 63 SUV, had been purchased by an Arab who then took it to AMG with a light blue beach towel he'd found on holiday in Egypt. "Can you make the interior this colour?" he asked. "Of course," was the reply. Anything is possible.

Mark Nichol