To appreciate the original BMW X5's impact on the market, you have only to consider for a moment which other SUVs were available to buy in 1999.

The Land Rover Discovery looked like farming equipment and had all the durability of a falling comet. The Toyota Land Cruiser could brush off a comet strike, but only because it was the size of a continent.

Elsewhere, Mercedes' M-class was still a body-on-frame calamity, and while the Lexus RX wasn't, it drove like it might well have been. Only the Jeep Grand Cherokee had the right image – and that was American.

When BMW's newcomer arrived on the scene, the writing was on the wall. There was no antecedent for the X5. Before the original, E53-generation X5, BMW had shown no interest at all in the market for 4x4 machinery. Then, in 1994, BMW acquired the Rover Group and, with it, Land Rover.

The manufacturer learnt much from its ownership of the troubled British brand by the end of the 1990s. But it was still smart enough to mould its 4x4 in its own image, dubbing the first X5 an SAV – Sports Activity Vehicle – that prioritised on-road manners over off-road ability.

Over two generations, the X5 racked up 1.3 million sales. With this latest version, the F15 generation of the X5, BMW has promised improvements across the board – particularly with a view to improving efficiency – as it plays catch-up to a new breed of Mercedes-Benz M-class, Volkswagen Touareg, Range Rover Sport and Porsche Cayenne.

Has BMW now managed to overtake its newer and much-improved rivals rivals? Our comprehensive test will reveal all.

First drives

Find an Autocar car review

Driven this week