If the narrow, twisting, dipping roads around the English Lakes in the grip of winter seemed an inappropriate place to test a car as big and powerful as the Mercedes-Benz 450SEL 6.9 - a car with the image of a chauffeur-driven limousine rather than a sports saloon - then the proof of the pudding was in the driving. It surges away with the burble only a bog V8 can make and the sort of acceleration - 0-60mph in 7.4sec - one usually finds in the most potent sports cars. A couple of tightish bends appear, separated by a crest and a dip, and it wallows a bit on its hydro-pneumatic suspension and you think perhaps that it wouldn't be all that hard to get into a lot of trouble, but then you're heading for more open road, gliding along and nestling back into the soft brushed velour upholstery that makes the interior seem rather more inviting than in most German cars, and Mercedes in particular. It is quiet, it is smooth and it is fast. The V8 provides 286bhp but it's the 405lb/ft of torque, coupled to a three-speed automatic transmission possessing such a good torque convertor, that rally matters here: that much heft makes a kerb weight of 4257lb seem feather light, and an especially good power steering system makes it all so easy to manage. The complicated hydropneumatic suspension, in essence, not dissimilar from Citroen's, provides not only a first-class ride but permanent self-levelling as well and before you know it, you're running along everyday highways at an oh-so-relaxed 90mph. This is high-speed comfort as well as efficiency; a high-speed express for high-speed businessmen.
But they'll be fools if they leave the driving to the chauffeur. Swing off the highways or the motorway (and if you wish, the 6.9 will effortlessly take you above 140mph when you have the space) and onto the tiny, weaving roads of a place like the lakes and you'll find that this great hunk of a car does indeed handle like a good sports car. Strangely, there is no real impression of bulk. One is not aware that it is much bigger than a W123; if anything, it feels even tidier than the smallest car in Mercedes' range. Such power endows the car with a spriteliness that reduces both the weight and the proportions to an insignificant level, for despite the impression of compactness that might be greeting the driver as he gets on with the job of enjoying himself, there is a great deal of luxuriously-appointed room behind him. But the presence of so much weight means on the one hand that in any bend, other than a long, high-speed sweeper, taken hard there will be a roll-induced oversteer. Should the weight not bring it on, a decent prod on the throttle certainly will. Thus the roadholding may not be sensational bu the ultimate standards, but the big Merc certainly does have the handling to make up for it. The tail comes out and a quick flick of the wheel catches it; you can bring it back with a throttle lift-off or simply through the cars inherently good manners, or hold it out with a steady power application. You can induce understeer into bends should you wish to do; you can change attitudes at any time within the bend. you can really fling this big limousine about, for its handling and balance and its precision is impessable. You will, however, get a little by way of lurching as the body goes one way and then the other; the suspension is set to provide long wheel travel.
At low speeds, the ride can feel slightly firm, in the usual German manner, over rough surfaces; after that it falls into the category of those rides that are sufficiently good for you never to think about them. Under acceleration, there is a decently appealing burble from the SOHC, injected, dry sumpV8 but at any steady-throttle cruising speed, including 140mph, there is no sound from beneath the bonnet. There's not much road noise to be detected from the front seat either but absolute silence is staved off by the flurry of some, fairly subdued wind noise around the front pillars from about 90mph upwards; it does not increase in volume with the speed. Instrumentation is clear and efficient according to the current Mercedes system. The automatic transmission is worked by flicking that distinctive little lever about in its zig-zag slot; it works as quickly and responsively as ever, moving as much as most manual shifts would as you get on with the business of enjoying yourself by exploiting the opportunity for some really satisfying left-foot braking. The shifts of the three-speed transmission aren't, however, quite as smooth as those of the four-speed on the smaller cars; that is to say, you can sometimes detect them.
The seats are adjustable for height, of course; but through Mercedes' clever twin sliding runner system, not by hydraulics: the pull-out knob on te dash just below the speedo is to adjust the cars height for one reason or another, as outlined in the handbook. The driving position is excellent of course; the Germans so rarely get that wrong. So are the seats themselves, and so is the finish. An electrically-operated sunroof backs up powered, tinted windows and the usual Mercedes central locking system is present. This is pretty much the complete saloon, packed, because of its punch, and its especially adroit handling, with rather more character than the other Mercs. And if you're worried by the £21,95 price tag - especially when an XJ12 is a mere £ 8700 - console yourself by thinking how much you'll save by sacking the chaufeur, and that the first 50,000miles will be maintenance-free apart from oil changes, and you'll only need those once every 10,000miles.