Mercedes R350 CDI

It’s hard to see why the R-Class hasn’t been more of a hit with wealthy families. On one hand it’s a practical seven-seater and – with all the seats folded – a superb load-lugger. And on the other, it’s a luxurious cruiser and a stylish way to travel. More powerful but highly efficient diesel engines add to the appeal, as does the long list of standard equipment. So it’s an enormously capable car. The trouble is, Mercedes hasn’t done quite enough for it to break out of its low-volume, ultra-niche corner of the market.

Part MPV, part SUV, part luxury tourer... Mercedes’ R-Class has always had an identity problem. That has meant only 3,100 have been sold here since 2006.

Can the new second-generation version change all that?

Gone is the original’s goggle-eyed look, replaced by a more mature take on the family face. A new bonnet, more upright grille, sleeker headlamps and sculpted bumper give the front a radical look. At the rear, standard LED tail-lamps match the sparkle of the bi-xenon headlights.

The interior is as luxurious as that of an E-Class, but it has room for seven in leather-lined comfort. Fold rows two and three, and our long-wheelbase car offers 2,385 litres of space – only 173 litres behind Land Rover’s Discovery. Standard kit is as generous as you’d expect for a £45,000 MPV.

Two models will be available from launch: the rear-wheel-drive R300 CDI and this LWB R350 CDI 4MATIC. Our car offers 40bhp and 110Nm more than the previous R350 CDI, at 261bhp and 620Nm, yet economy and emissions are improved by nine per cent.

The V6 diesel has a muscular power delivery, and the upgraded 7G-Tronic auto delivers seamless shifts. But given the car’s weight, it still feels a bit sluggish.

The 4WD offers strong grip in corners and would come in handy over muddy fields. Importantly, though, it could persuade buyers out of SUVs. We’d recommend adding the optional adjustable air-suspension, too – it suits the car’s laid-back demeanour well.