The Mercedes SL65 AMG really is a vehicle that takes excess to excess. Designed for buyers who think the 530bhp V8 SL63 AMG is a bit short of puff, the SL65 gets a 6.0-litre, twin-turbocharged V12 engine with 621bhp and, wait for it, 737lb ft of torque.
That's enough shove to propel Merc's super-luxurious roadster from 0-62mph in 4.0 seconds, and to a top speed of 155mph or 186mph, if you stump up a bit extra to unlock the AMG Driver's Package.
Shelling out cash is an integral part of the SL65 AMG experience, mind you because the extra you pay over an SL63 AMG is a frankly astonishing 58,000. At 168,000, it costs the same as Merc's full-house gullwing sports car, the SLS. Can it possibly be worth it?
What's the 2013 Mercedes SL65 AMG like to drive?
You'd expect a car like this to have effortless pace, and the SL65 AMG certainly delivers on that front. In fact, it'll take you a while to learn how to drive it smoothly, such are the levels of poke available from virtually no revs. The engine is classic AMG V12 fare, with huge reserves of torque and excellent flexibility.
The transmission is a seven-speed automatic system (Merc's dual-clutch gearbox wouldn't be able to cope with the SL65's torque). It's not the smartest set-up on the market should you ever feel the car slow to respond, it'll almost certainly be down to the 'box making up its mind about something rather than any deficiency in the engine but in the most part, it's capable enough for rapid, relaxed progress.
This means the SL is at its best as a sports tourer (a seriously rapid one, in this case); stick the suspension controller into 'Comfort' mode and enjoy the mix of direct, responsive steering and excellent ride quality.
The V12 proves a refined companion to this sort of activity perhaps even a touch too restrained, in fact, because if it has one weakness, it's that its exhaust note is a little on the quiet side. Merc would probably argue that you'd buy the V8 if you want a trademark AMG burble; we'd say that it seems a little strange to pay so much more for less aural excitement.
It seems churlish to mention fuel efficiency on a V12 twin-turbo, but the SL65 is more economical than the previous-generation model. It's all relative, though; its CO2 emissions are a hefty 270g/km and while the official average economy is 24.4mpg, you'll be lucky to better 20mpg in real-world usage.
What's the 2013 Mercedes SL65 like inside?
The SL65's cabin has a high-quality feel, with lots of double-stitched leather, interrupted only by carbonfibre and metal inserts. The switches all feel premium, too and the standard kit list includes important elements such as Mercedes' 'Comand' infotainment and sat-nav system.
There's plenty of room on board for two people and a reasonable amount of luggage although you will have to squeeze the bags into a smaller area if you want to make use of the SL's beautifully engineered folding roof.
It's worth remembering that there is still a (hefty) options list, should you want to add further clout to your SL65's price. Items such as carbon-ceramic brakes, premium paint colours (including a matt finish) and the impressive 'Magic Sky Control', which increases and decreases the amount of light allowed through the glass roof at a touch of a switch, can easily add thousands. Our test car carried an on-the-road bill of almost 190,000, which is more than you'd pay for even the SLS Roadster.
As with all SLs, the SL65 AMG is perfectly happy with its roof down; sure, there is wind noise (particularly at the sorts of speeds this car can achieve), but in most environments the occupants will be able to talk to each other without shouting.
Should I buy one?
There are some people who will not consider the merits of the SL65 AMG over the SL63; they'll simply see the additional number, assume it's the best and barely notice the 60k price difference as they sign on the dotted line. For these customers the SL65 is an awesome tool extremely luxurious, devastatingly fast, beautifully built and impressively refined.
For anyone blessed with the gift of sanity, though, it is hard to see the SL65 as anything approaching a rational purchase. For all its extra expense, this car is barely any quicker than the SL63 in the real world. Nor is it that much more luxurious inside and if anything, it has less character when you're on the move, due to the V12 engine's more hushed tones.
If you want a high-performance SL, therefore, we'd stick with the SL63 or better still, go for the SL350. It's hardly slow in the real world, still offers open-top cruising, and is the thick end of 100,000 cheaper.
What Car? says...
Mercedes-Benz SL63 AMG
Porsche 911 Cabriolet
Engine size 5980cc V12
Price from 168,285
Torque 737lb ft
0-62mph 4.0 seconds
Top speed 155mph
Fuel economy 24.4mpg