First glance: Audi's big gun is magnificent S7 Sportback WE'RE a strange bunch. Sell us Brits a small car and we insist it has a hatchback. Small cars with boots are given the elbow with quite some conviction. As you begin to spend more money, something strange has tended to happen. This behaviour reversed. Aside from big SUVs, the idea of a premium five-door car never gained significant traction. Even cars that looked as if they should sport a tailgate often featured stubby boots instead. It's only in the last few years that a change has come about and Audi is never slow to tune into buyer trends. Its A5 Sportback and A7 Sportback models couldn't have been timed better and now we have a model that stretches what buyers will pay for a big hatchback that little bit further. "Hatchback," however, seems an entirely inadequate way of describing the awesome 414bhp Audi S7. It looks rather quick... The S7 is not a model that, like the S4 or S6 models, has a long history to live up to. As such, it's a car that many will take on its own merits - and those merits are quietly impressive. Its 4.0-litre twin-turbocharged V8 might not offer the soundtrack of a V10 but it seems an engine that's a little more in step with the Zeitgeist and one that won't leave many wanting more power. With a massive 550 Nm of torque, the S7 will sprint to 100km/h (62mph) from rest in 4.7 seconds, its power being deployed, predictably, by quattro all-wheel drive. The top speed is limited to 155mph, although Audi insiders reckon it will knock on the door of 190mph were the limiter removed. But at the same time, there's Cylinder on Demand technology that allows the TFSI engine to cut four of the cylinders when cruising to aid efficiency. At low speeds or when the driver demands more power, the other four cylinders instantaneously spring back into life. Air suspension is fitted as standard, as is Audi's Drive Select driving dynamics system. The driver can then tune throttle pedal response, shift points of the S-tronic transmission, the assistance to the electro mechanical steering and the characteristics of the adaptive air suspension. It's as clever as it sounds. What sets it apart? Perhaps the most overt items of styling are the S7"s wheels - 19-inch in standard guise, ranging up to 21-inches for the frankly inadvisable options. Tucked behind them are S7-stamped brake calipers, while the trademark S aluminium mirror housings catch the eye. Nine exterior colours are available. At 4,980mm long, the S7 is a seriously big car, although the sleek coupe-like profile helps disguise any notion of bulk. The cabin is designed to comfortably seat four adults - and can seat five - while there's a sizeable boot that can expand to 1,390 litres with the rear seat backs folded. At motorway speeds, a spoiler extends from the rear hatch to improve stability. Aside from the S7 and V8T badging, look out for the redesigned single-frame grille, the front bumper, the sculpted sills, the rear bumper, the diffuser and the tailpipes. A lot of work has gone into endowing the S7 with just the right amount of visual muscle. ... and what's the damage? With "standard" cars priced at around £62,000, the S7 doesn't seem bad value for money at all. There aren't many cars that can touch it for its combination of power and presence. Perhaps the most interesting thing about the S7 is that it isn't trying to be something it's not. It's never going to be a track car and doesn't pretend to be. It's a car for getting a hustle on big roads and that ability doesn't always come cheaply. Whether it does it a whole lot better than a 3.0TDI A7 which retails at around £20k less is a value judgment you'll need to make. Equipment levels are predictably overstuffed. Some of the finishing speaks of a real attention to detail, with S badges, the S7 logo in the illuminated door sill trims and aluminium shift paddles, all burnishing the look and feel rather agreeably. Also fitted as standard are xenon-plus headlights with LED daytime running lights, a driver informaton system with colour display and an MMI radio plus audio and operating system. Do I need an oil well? If you can keep your options selections on the right side of reasonable, you can help cap off depreciation to an extent. Big petrol-engined cars lose value quicker than diesels, so you'll need to keep both eyes open when going into S7 ownership. Fuel economy is one area where you'll probably be pleasantly surprised, that Cylinder on Demand technology making the car very efficient on long motorway cruises and helping contribute to an overall economy figure of 29.4mpg. Best of luck replicating that though. You'll probably find the throttle pedal has strangely addictive qualities. comfort and joy The Audi S7 is a car that merits a measured approach, its blend of talents making it like a mainstream A7 with a bit extra in hand rather than a hard-riding RS-style Audi that's been tuned back a couple of notches. You'll enjoy the S7 for its smooth ride, its effortless powerplant, the dizzying amount of technology built into it and its slick-shifting transmission. Couched in these terms it's hard to judge it anything but a success. Above all, it's a mature car. That hasn't always been the case with some S model cars bearing the four rings, as they often prioritised big power over virtually everything else, but the S7 is a more rounded contender. What's the definition of cool? Not having to try too hard? The S7 barely breaks a sweat. CAR Audi S7 Sportback PERFORMANCE Max speed 146-155mph; 0-62mph 5.3-8.3sec