IT may be credited with kicking off the whole prestige SUV movement, but there was little question that, at the end of its seven-year life, the Mercedes-Benz M-class had been out-pointed, out-performed and outclassed by just about all competitors. The all-new version rectifies all of this. The M-class is now entirely competitive with its peers on the open road, while it offers the potential of being a more capable occasional off-roader than it was before. The substitution of a ladder-frame chassis with unitary construction saves weight while allowing a larger, tauter body that takes full advantage of the all-new petrol V6 engine as well as the forthcoming V6 turbodiesel. It looks tough and substantial, yet has been carefully designed to give sedan-like aerodynamic drag figures. Bigger, more powerful, more economical. It’s hard to argue with that.