I'm looking for a reliable, fuel efficent diesel car.

Hi Paddy,

Well, with that kind of budget to shop with you're well into the price range for most compact 1.6 diesel hatchbacks, and I'm talking new (or nearly new if you're looking to maximise the bargain). 

So I'd recommend going for one of Volkswagen's new trio of compact cars, the Golf, Octavia or Leon (sadly the Audi A3 is probably out of your price range).  All three are excellent, solidly build and share the same frugal 1.6-litre TDI diesel engine. Of the three, I'd suggest going for the Leon as it gets you the best all round car, but the classiness of the Golf or the practicality of the Octavia are equally strong draws. Can't go wrong with any of them really.