This gas-guzzling monster is strangely seductive, says Michael Booth

Would suit Ryder Cup wives
Price £66,865 (as tested)
Maximum speed 143mph, 0-60mph in 7.1 seconds
Combined fuel economy 24.4mpg
Further information 0800 181 361

If industrialised nations can buy the excess carbon-emission quotas of less polluting countries, why can't car owners do the same? This occurred to me as I torched my way through enough fuel to light a Brazilian favela for a month pottering down to Waitrose in the new Mercedes-Benz GL.

Around town, the GL drinks diesel at the rather scandalous rate of one gallon every 18.1 miles, belching out pollutants as it passes (310g of carbon dioxide per kilometre). This is an improvement over its rival the Range Rover, admittedly, but still enough to make even Dick Cheney blanche.

So what if GL owners could pair up with, say, Smart owners to balance out their pollution? If we take the average car's carbon emission to be around 170g/km, then the Smart has around 50g/km spare. A GL owner would have to buy the emissions allowance of three Smart owners, of course, but I am sure they could rustle up the cash. We aren't exactly talking about a demographic toiling in the poverty trap here; they'd just have to cut back on Swarovski dog collars, or something. They could even carry little photographs of their emissions-allowance donors in the window, like people who keep snaps of adopted African children pinned to the fridge.

In many ways, this car deserves to be more politically palatable. Like it or not, it commands respect. It is impressively built, fearfully powerful and shamelessly colossal. The first time I drove the GL, I climbed straight from the driver's seat of a Maserati Quattroporte (dedication, that's what this job's all about!), but I swear the Mercedes was the more fun to drive. I am currently lobbying my local MP for the marriage laws to be amended to allow human/automobile couplings, so in love am I with the Maserati, but the Mercedes was phenomenally accelerative (0-60mph in seven seconds), yet in Sport mode its 2.5-tonne bulk was so well controlled that winding country roads weren't the usual cause for concern that they can be in other big, high cars.

There's none of your slow, woolly electronic-steering nonsense here, just a plain old rack-and-pinion job; the brakes are more than up to the job too, offering almost sports-car levels of feel. Big windows and a simple, square-framed shape help you place it easily on the road and in the car park, despite its five-metre length; unlike the smaller ML or Range Rover, it seats seven adults. Even the rear two seats are properly human-sized; they are the most spacious of any seven-seater in fact, and even have their own sunroof. What's more, they fold at the touch of a button, which should mean a few hernias rest easy. A serene, leather-trimmed interior - one of the most soothing of any contemporary car - velvety seven-speed automatic gearbox and more gadgets than Jimmy Savile's armchair make it worth every penny of £50,000.

Unfortunately, the GL I borrowed costs £66,865, which literally made me gulp when I first read it on the spec sheet. Parked next to a Range Rover, the GL is the larger car, it's faster and more frugal too, but it lacks the presence of its British rival and when the Range Rover gets a V8 diesel - which is coming soon - I imagine there'll be a lot of head-scratching in certain parts of Hertfordshire and Dubai. Discretion may well be the better part of valour down the golf clubs and gymkhanas of the Home Counties but I can't help feel that the GL could do with a dose of the R-Class and CLS's loucheness. That and an oil derrick in the boot.

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