Mercedes-Benz GL 420CDI - Diesel Road test

Mercedes-Benz GL 420CDI

Make way for the new GL. When it struts ashore from its Alabama factory this September, there's little chance of missing it: it's the same width as the ML, but takes up more tarmac, nose to tail, than a Discovery or a Range Rover. Just a loaf's length short of five metres, this bruiser is unlikely to soothe the ire of our anti-4x4 brigade, though it's big enough to stand in if the school bus breaks down, which might please them.

The GL is very much a Sport Utility Vehicle in Mercedes' terminology but, on the unpredictable backroads of Iceland, you soon realise this is nonetheless a proper offroader, capable of keeping its cool where others might easily capitulate.

One of this country's most frequent warning signs is for a 'Blind', which sounds like a handy insult but is a warning, as you might guess, that something nasty lies beyond yonder hump. Invariably, it can herald an abrupt change from tarmac to loose gravel, interspersed with lumps of tyre-popping lava rock. Armco is rare as sunstroke, with dramatic drops just a wheel flick away. Can the GL cope or is it too busy trying to look mean?

In down-town Reykjavik, the signs are promising. The steering is very precise with no need for constant rectification. Out on Route 1, the main island-encompassing highway, another gold star is soon earned for ride quality. Machines of such expansiveness as this can feel a little flustered by uneven camber and often don't settle. The GL, thanks to Airmatic suspension and an adaptive damper system (ADS) as standard, makes velvety work of standard surfaces. It's oh-so quiet too, as that local pop star might say.

Out on the old Kaldidalur road though, those pesky Blindhæds lie in wait. In ancient times, this was the lonesome route that connected farms in the west to the original parliament. Its highest point passing sky-high between two ice caps of the Langjkull Glacier. Even by the standards of Liverpool City Council's Highway Maintenance, this is barely a road at all - imagine a quarry bed striated with washboard-effect patterns, stubborn ruts and occasional craters. Ask a vehicle like this to be nimble at speed, on a road like this and it might lose grip and drift like a wounded Zeppelin, piloting everyone inside to death by lava rock.