Road Test: Land Rover Freelander 2.0 Td4 E Station Wagon 5dr

Never a decent traffic jam when you really need one, is there? I'm in central London in rush hour, desperately hunting for a decent globule of congestion to try out the Freelander TD4_e's stop-start system, but the roads are spookily deserted.

Maybe it's all part of the bizarre quantum shift which has caused such a defiantly rural marque to invest in such defiantly urban technology. Yes, an eco-friendly Land Rover might seem odd, but as evidence that no one is immune to the inexorable rise of green - and that you'll find more Freelanders in Sunbury than Snowdonia - it's pretty compelling.

As are the numbers. This is the cleanest Land Rover ever built: a 2.2-litre diesel Freelander fitted with stop-start technology, regenerative braking and a bunch of revised auxiliary components - alternator, water pump, stuff like that - to reduce the engine drain. Hardly revolutionary, but the benefits are impressive: economy jumps from 37.7mpg to 42.2mpg, while emissions are down by 15g/km (and a whole tax bracket) to 179g/km of CO2. According to Land Rover, the improved economy should save you around £13 a tank, or £680 a year.

In the total absence of any traffic, I decide to recreate gridlock conditions by stopping haphazardly in the middle of the empty roads. I'm happy to report that the stop-start system, er, stops and starts just as you'd expect: ease to a halt, slip into neutral, take your foot off the clutch and the engine subsides. Stick it back into gear, and the diesel putters back to life, with nary a rattle nor cough.

Don't worry: you won't get stuck in quicksand or halfway across the Ganges with a dead engine - engage one of the hardcore ‘terrain' modes, and the stop-start system disengages, just as it does if the cabin or engine oil aren't up to temperature. And, if you really miss the sound of a diesel idling as you sit in traffic, you can completely disable the system.

So what's the catch? Well, though the stop-start technology comes as standard - and with no increase in cost - on every diesel Freelander with a manual 'box, you can't get it in automatic or petrol flavour. They'll come soon, though, along with a whole bunch of other green tech culminating, says LR, in a diesel hybrid by 2010.

But this'll do just fine for now. No, a Land Rover will never have quite the same green cachet as a Prius, but every little helps, as they say. And if you're into the whole lifetime-cost thing, don't forget that the Freelander is built in the UK, so it's greener than you might think. Its mysterious traffic-repelling abilities are an added bonus too...