Subaru B9 Tribeca

You'll be familiar with the phrase 'there's no such thing as a free lunch'. And it's true: you very rarely get something for nothing these days. Just ask Subaru, whose B9 Tribeca SUV sums up the old adage so well. Yes, it's an eye-catching, 3.0-litre flat-six-powered, leather-trimmed, four-wheel-drive seven-seater. But it comes at a price: a hefty, 22mpg kind of price - if you're lucky.

As if that wasn't bad enough, there's something else that turns the arguably unacceptable cost of family motoring into an even greater irritation - a fuel tank that's way too small. With a capacity of only 64 litres, it simply isn't up to the job on a car this thirsty.

I've had to drive pretty frugally to achieve the above economy figure, too. But even motoring with a featherlight right foot, the car's range is no more than 280 miles. So on my 120-mile-a-day round trip commute, that means filling up every 48 hours.

And no sooner have I topped up the tank with another £50 worth of unleaded and left the filling station than the electronic needle is clearly beginning its journey south again.

Drive it hard - which the Tribeca's 241bhp flat-six engine positively encourages you to do - and the tank empties like a bath running out. Even the cashier at my local garage forecourt is getting fed-up of seeing me.

This familiarity with the Subaru is also down to the fact it stands out from the crowd. Thanks to its high-mounted headlights and snout-like grille, I'm becoming used to receiving plenty of stares and double-takes. I even got a wave from a fellow Tribeca driver this month, although that's a rare occurrence - there aren't many around, and I'm not surprised with these running costs.

Even though it's billed as a seven-seater, only the smallest of children could travel for any length of time in the back. My own teenagers have all had a go, and none of them can cope with the tight legroom and foot space.

However, there's no doubting the Tribeca is luxurious. The leather seats are supportive, all the controls and instruments are on a space-age sweeping facia, while the touchscreen sat-nav doubles as a monitor for the reversing camera.

The Subaru also has a roof-mounted DVD system for rear passengers and an iPod socket in the centre armrest, which allows me to listen to my favourite tunes on the car's excellent stereo. In fact, it's absolutely perfect for my current playlist: Fuel If You Think It's Over, Tanks For The Memory and Fill Me Up Before You Go-Go...