Mercedes has updated its GL-class luxury SUV for 2013.

Of the suite of revisions, the crucial update for fleets is the 24% and 13% improvements in fuel consumption and emissions respectively from the GL350 3.0-litre diesel engine, with figures of 38.0mpg and 209g/km.

That’s still not enough to get it to the front of the prestige 4×4 pack when Audi’s Q7 musters 189g/km, and there’s an admittedly smaller BMW X5 on the way with front-wheel drive and 149g/km, but it’s a step in the right direction nonetheless.

Elsewhere, the big Mercedes is indicative of such models: teeming with equipment – safety, off-road driving aids and a swish sound system being but a few of the highlights – and the 258hp V6 engine isn’t short of grunt.

You’re well aware of its imposing size on the road, but it is refined and there’s plenty of glass, so all-round visibility is good. It’s comfortable, too, but the ride can become a little bouncy at times. 

Only one other variant is currently available – the GL 500 with a 4.6-litre 435hp V8 petrol engine – which, despite being cleaner than its predecessor, is likely to figure even lower on fleet sales charts.