Choose a 'Green' compact car next timer you rent from Hertz in the UK and you'll most likely be handed the keys to one of these cars, the Ford Focus 1.8 TDCi. Often overlooked by renters, you can drive a more economical equivalent of a class C compact hatchback for the same, and sometimes less, than the regular daily rate of a class C vehicle.

Hertz chose the Focus Duratorq diesel for it's low CO2 emissions (approx 137g/km) and good fuel consumption (54.2 mpg on a combined cycle). For a car of its size, that's not bad at all, although devoted tree huggers who still need to drive should consider the miserly Ford Focus ECOnetic that squeezes even better fuel consumption out of improved aerodynamics and less weight in the car.

The latest Focus is a smart looker - a 3 and 5 door hatchback and 5 door estate versions (the 4 door saloon isn't sold in the UK). Getting one at a rental counter is also a real treat for North Americans, who have to make do with a mildly restyled version of the first generation Focus. The build quality is generally excellent - on all the versions I've seen the body panels have a consistent fit and everything that opens/closes does so with a reassuringly solid sound.

Inside, materials are of good quality for a family hatchback. Some of the plastics are a bit scratchy looking, but then at this price level that's rarely a surprise. The seats are comfortable and supportive, and compared to some cars in this class, the Focus has a comfortable weightiness to its controls and steering. The standard fit sound system is good, but the ease of use of the controls has been sacrificed to make them look all smart and symmetrical on the dash; I found it hard to find the preset buttons while driving, although would probably learn with time.

I took one on a major road trip - 650 miles by motorway and A-road from Scotland to the Midlands and back. On the twisty bits the Focus is well poised and composed, yet still fun to drive. The diesel has a responsive kick when you need to change down for more speed on the go (excellent for quick overtaking) although 0-60 acceleration is not this car's strong point. Over that trip I managed a solid average of 45mpg according to the in-car computer, and I reckon you could better that if you go easy with the right foot.

A smart family choice or compact business car, but to get the advantage of the fuel consumption you'll need to spend most of your time on A-Roads and motorways.