Road Test: 2013 Mercedes-Benz SL500

The Mercedes-Benz SL 500 continues the tradition of mixing glamour and crushing ability.

The SL has remained Mercedes-Benz's GT car for more than 60 years, and the latest generatio is undeniably the best yet. Sarah Dea / The National

The Mercedes-Benz SL has, from the day it was born in 1952, always been one of the world's most desirable cars. What started out as a racing machine with gullwing doors and more glamour than a Hollywood starlet - even winning the 24hrs of Le Mans - has slowly evolved into what we see before us here: only the sixth generation in as many decades.

That kind of slow, measured evolution is what has made the car just so good, so complete in every respect. Granted, there has been the occasional mid-gen facelift, but for a model to go fundamentally unchanged for a whole decade it has to be truly excellent to start with. Mercedes-Benz knows that whatever they do to the SL it will have to last a very long time, while other pretenders to its throne come and go.

SL might stand for Sports Leicht (Sports Light), but this is no sports car. Instead, it's best viewed as a big, luxuriant grand tourer that combines effortless performance, a cosseting ride and every conceivable gadget in its cabin. And this new one is no exception.

Until the SL63 AMG roars onto the scene, this SL 500 is the range topper, with only the V6-powered SL 350 beneath it. The 500 has, shoehorned into its engine bay, a twin-turbo, 4.7L V8 that's good for 435hp and an electronically governed 250kph maximum speed. Acceleration is incredibly swift, with the SL 500 cracking 100kph from rest in just 4.6 seconds, which is almost Porsche 911 territory. But as I said, it's no sports car.

In 500-guise, the SL weighs 1,785kg, which might sound like a lot but is, in fact, lighter than its rivals and no less than 125kg lighter than the previous model - a weight saving that most manufacturers make a terrific song and dance about. If this was a Lamborghini it would be a Superleggera, and that's down to its almost entire aluminium construction, where the old SL was a predominantly steel structure. Merc's engineers have proudly gone on record as saying that, with this new SL, they were working on the boundaries of what's possible with aluminium cars, and they have done themselves proud; the car is quite incredible.

So it's lighter than before, yet it's also significantly wider and longer. And that pays huge dividends inside the SL's wonderful cabin. My test car has been specced with an unfortunate shade of brown leather upholstery, which jars somewhat with the external metallic matt grey paintwork, but that's the only negative. The rest of it is an exercise in class, sophistication and a grown-up approach to design - it's a place that makes you feel good about yourself and the world.

At the pull of a toggle switch cunningly concealed within the centre armrest, the aluminium roof folds away in 18 seconds - something I decide to take advantage of while I still can (it's getting warmer, isn't it?). Roof up or down, the SL is a disarmingly handsome brute and, to these eyes, the best looking variant since the third generation, which went out of production back in 1989. Its front end, in particular, is overtly masculine and is way better resolved than the unfortunate (and rarely seen) facelift of the previous model. This, make no mistake, is a car that turns heads wherever it goes.

And boy, does it go. More suited to straight-line speed and point-and-squirt overtaking moves, the turbos gently whistle as they spin up before catapulting the car with breathtaking, muscular power. The engine remains cool, calm and collected, never seeming stressed, only letting itself be heard when you're really gunning it. The rest of the time, it just burbles away unobtrusively, just as befits one of the world's finest cars.

Refinement has always been a key part of the SL's appeal, and the only thing that lets down this test car is its (optional) AMG sports suspension. On smooth surfaces it's a dream but taking speed bumps even at crawling speeds results in some horrible bump-thump. The car is a natural cross-continent tourer, not a trackday weapon, and I suspect the standard suspension would be better suited to its rather benign nature.

Roof down and with windows and rear windbreaker in place, my wife's hat remained on her head, even when pressing on, showing just how far convertible design has come in recent years. But there is a drawback to top-down motoring in the SL, and that's the folding roof's intrusion on boot space. The cabin is replete with plenty of cubby boxes and handy storage pockets, though, so with some careful planning you might just manage to squeeze in enough stuff for a weekend away sans roof.

And that's what this car is all about: the good life. It's a status symbol, of that there is no doubt, but it's one we don't resent seeing other people driving. Because it's sheer class on wheels - a supremely stylish expression of German engineering prowess - and this sixth generation represents a massive leap forward in all respects.