New Mercedes SL - First Drive (2008 onwards model)

The iconic Mercedes SL gets a thorough facelift, together with some new engines and a very interesting new gearbox - keeping it in the game against recent all-new competitors.

The Mercedes SL is a car with a long and illustrious history. Most have been suave looking grand tourers that offered smooth relaxing drives with the exhilaration that only roof-down motoring can bring. Having sold 630,000 of them over the past 50 odd years, the car is important not just in itself, but also as the halo car for the wider Mercedes range. Cars like the flashy and pricey SL say much about the brand, even to those with much less money to spend. In that light, extending the SL's reputation in this new model is crucially important for the Stuttgart-based giant.

This 'new' SL is in fact the mark 2 in effect of the car's R230 fifth generation that arrived back in 2001, and will probably be the last batch of major changes before the car is replaced entirely in around 2011. The SL is notable for being the only car in its class apart from the Lexus SC430 to have a folding metal roof rather than a canvas one.

Unlike many facelifts everyone will easily notice that this is a new model. Out go the dual headlamps of the old, and in come rather neat looking CLS-style wrap-around lights. Out goes the three-strip grill, to be replaced by a single silver fin. And in the final new obvious feature, we get bonnet bulges throughout the range, even in the entry-level SL280 (which won't be sold here). Does it work? Many considered that this model failed to live up to the most successful looking SLs of the past, accusing Mercedes of pursuing the brash vulgarity demanded by some of the younger sections of its customer base.

In the process, it alienated those that remembered the classic open-top Benzes of old. Certainly the more cultured look of the lights and the elegant simplicity of the grill go some way to fixing that, but traditionalists are unlikely to be so kind about those bonnet bulges - nor about the fake-diffuser bumper which is the main change at the back. For me, while I thought it looked elegant in a Germanic sort of way in the sharp contrasting sun of the Californian spring, the class leaders in the looks department remain the Jaguar XK and the Aston Martin V8 Vantage Roadster.

On my trip to drive the new car in and around the excellent and mostly empty San Bernadino mountain roads to the north of Los Angeles - and then later Palm Springs out in the desert - I drove all the models that will be of most importance in sales terms in the UK, starting with the entry level - and biggest selling - £65,000 SL350. This has an all new 3.5 V6 engine that boosts power by a full 40hp, gives a bit more torque, but still delivers better fuel economy than the old one. Indeed its 316hp is more than this model's SL500 offered back in 2001.

The new engine is a delight - delivering a surprisingly deep-throated V6 rumble and eager free revving power delivery. It may lack the power of its bigger-engined brethren - but it is of course lighter too. On challenging twists and turns I found the car could keep up with an SL600 in front of us - especially when using the paddle shifts to shift down to produce the grunt to get out of a corner - and indeed the car only losing out against its V12 big brother inevitably on the long straights. It achieves the 0-62 run in a creditable 6.2 seconds and like all SLs, is electronically limited to 155mph.

Moving up to the SL500, I found its V8 surprisingly languid in comparison, offering a fairly minor 20% more power but at a cost of 80 more kg (or equivalent to one average person or so) and while it will do the 0-62 sprint in 5.4 seconds, it doesn't feel especially fast. Day 2 of our trip is 'AMG day', giving us the chance to drive the two performance models at the top of the SL range, the V8-powered 514hp SL63 and the 612 hp SL65 V12 twin-turbo which have simultaneously arrived in the new guise.

The 63 heralds an all new gearbox. Previously featuring an older five-speed automatic, this has now been replaced by a new AMG-designed 'MCT 7' 'wet clutch' autobox that does away with the torque convertor in the never-ending quest to lower gearchange times. It bears certain similarities with the DSG system used by various VW group cars, and is perhaps halfway to the flawed robotised SMG systems employed on the BMWs M5 and M6. My verdict? Terrific.

It offers gearchanges that are rapid and smooth, and assuming your gear settings are switched to Sport or Sport +, it will give you a truly delightful automated blip when downshifting which had me and my co-driver howling with pleasure and doing an awful lot of it. The naturally-aspirated engine itself has a lovely deep burble to it which still somehow manages to sound refined; you can hear those turbines spinning, urging things forward. But - and it is a big but - this is a different beast from its supercharged SL55 predecessor, which brought an unheard of level of rawness to the range, doing much to cement the AMG brand in this country in the process.

That aspect has now gone during the change - along with about 66lb ft of torque - and some will cry shame. The 63 does introduce a launch-control function which sounds fun but in reality most buyers will use about once before the novelty wears off.

One might expect the monstrous SL65 to be a grunting rocket-ship. On the contrary it proves much more subdued than its V8 sibling. The twin-turbo V12 is super-smooth and - even with the roof down - you can barely hear the engine most of the time. It is quick - 0-62 in 4.2 seconds - but whereas the 63 reminds you of its potential with every rumble, the 65 operates almost like a stealth bomber: very potent, but under the radar. I think the AMG brand stands more for 'SL55' values, and it is still lumbered with the older five-speed gearbox since the new MCT device can't handle the V12's 738 lb ft torque load. On that basis the 65 doesn't really work.

And at a cool £50,000 more than the 63, the 65 represents a ludicrous waste of money. Interestingly, I got the distinct impression from the Mercedes engineers present at the launch event that they also regarded the 63 as the 'uber-SL', not the 65; the F1 safety car this season will be an SL63, not a 65.

The SL is a comfortable grand tourer in the old tradition, and as such can be expected to make sacrifices in the sporting department. Mercedes are keen to emphasise the new model's sporting credentials however, and they have done a good job at striking a compromise. The seats throughout the range are comfortable, supportive and electrically adjustable in a variety of different ways, and it's easy to get into the right driving position. Handling is strong, but predictably this story gets more complex as the engines get bigger and the cars get heavier.

I was impressed with the eager turn-in of the 350, its relative lightness giving enjoyable, rewarding pointiness from the new direct-steer system which gives a variable steering ratio as well as speed-sensitive assistance. As mentioned, the 500 doesn't have that much more power to support its extra bulk and when in close pursuit through bends it struggled a bit with oversteer, and as such I found it disappointing.

The AMGs are firmer of course but still comfortable. The SL63 AMG has much more power but - fortunately given some of the challenging roads we tackled in the mountains with looming precipices - the ESP keeps everything in check. There is a new setting called ESP-Sport which allows a bit more rear end 'wiggle' while still keeping an eye on you. You can now switch it all off but this is probably unwise on the public road. The 63's steering is eager, direct and precise, and all drivers will enjoy powering into corners, dropping a couple of gears and powering out again with urge and surge, helped by that excellent new gearbox.

Again, the SL65 AMG disappointed somewhat, seeming less eager and really showing its 150kg weight gain over the 63 - despite having a full 60% more torque.

The first thing to note is that the interior is hard-wearing and functional rather than sumptuous - but it will almost certainly stand the test of time, unlike that of the Jaguar XK which as been criticised on this point. The plastics used are of high quality, and the centre console will come in wood or neat looking alloy depending on your desire. The popular air-scarf from the SLK becomes available on the SL for the first time, a £420 option that pumps warm air at the temperature of your choice into the back of your head and neck via an outlet at the bottom of the headrest. It worked well and will certainly heighten comfort levels on cold winter mornings.

This new model also has a new Harmon Kardon sound system which Mercedes is very proud of and certainly sounded loud and proud. The dash itself is leather trimmed and smart, but the glovebox is slightly disappointing: cheap feeling and looking. Standard equipment is reasonable, but most buyers will have to spend at least 5% more than list to get all the options they need. It is however nice to see Mercedes matching the segment trends here and including useful items like a revised sat-nav system and Bluetooth phone link as standard on all models. A new three-spoked steering wheel is new, as is a new gear selector.

There will be no great environmental awards for this car. The smallest-engined model, the SL350, has a combined MPG of 28.5 and CO2 of 236 g/km. In comparison, the BMW 630i convertible does 34mpg and just 198 g/km of CO2. It's a shame Mercedes couldn't get their CO2 number the south side of 225 g, since cars above that level face some ongoing and serious tax issues - something a diesel option would probably solve; Mercedes denies this will happen, but many journalists are not so sure and indeed expect one in the next year or so. In the meantime, they should launch the SL280 over here pronto - this sneaks out of the CO2 death zone with 224 g/km.

Thereafter the economy gets steadily worse until it bottoms out with the V12's SL65 AMG on 18.7mpg and 362 g/km. The SL63 returns 20.3mpg and 330 g/km - but note that the car's peak torque occurs very high up the rev range (at 5200 rpm) - so I suspect this will translate into much worse fuel consumption than that amid spirited driving.

Safety-wise, the car comes with a number of frontal and side airbags, and a roll-over bar that will pop-up automatically if rollover is detected when the roof is down. This new model also heralds new headlight technology; bi-xenons are standard throughout the range, but an optional Intelligent Light System offers different modes for differing conditions: country, motorway, fog, cornering and 'active', the latter of which pivots the beam with the direction of the wheel.

The new Mercedes SL is a very impressive car. It moves the game on and keeps the car in the running against newer competitors from the likes of Jaguar, BMW and Aston Martin. However, the underlying car is getting on now and as the world moves faster, I can't help thinking that, especially in the looks department, having such long gaps between model changes is problematic even in this specialist sector. It certainly delivers a comfortable grand-tourer drive and the car certainly felt much at home in well-heeled parts of California.

The seven-speed auto gearbox works well, and I give a firm thumbs-up to the new MCT system used by the SL63. The new engine in the SL350 is excellent and the 70% of SL buyers who choose this £65,000 model will certainly be happy - not least because the other models save for the £101,000 SL63 are not meaningfully better and in some respects, contrive to be worse.