SEAT is among those leading the field when it comes to producing quick, slick cars capable of delivering that most rare of motoring commodities: the genuinely exciting, genuinely 'greener' driving experience.

With diesel now taking upwards of 40% of the new car market, the Spanish manufacturer's selection of sporty TDI-engined models is at the forefront of the shift towards the black pumps.

The so-called 'drive for diesel' - well documented by the Society of Motor Manufacturers and Traders (SMMT) - is now delivering virtually one million new registrations a year, and the trend towards oil burners is continuing to gather pace.

The successful Spanish car maker, which in the last year notched up near-record sales of almost 35,000 cars here and has just celebrated the construction of its 16 millionth vehicle, is ideally placed to help fuel this shift thanks to its fast, frugal Ibiza FR TDI, Leon FR TDI and Altea FR TDI.

The three - all neatly characterised best as hot hatches with a conscience - wring every ounce of mph, and mpg, from their turbocharged, direct injection powerplants.

The Ibiza, for instance, offers 130 PS from its four cylinder turbodiesel: enough power for a sub-ten second 0 to 62 mph time (9.3 seconds, to be precise) but also enough economy to offer 54.3 mpg on the combined cycle. All this, yet CO2 emissions are just 139 g/km.

The Leon, meanwhile, is even more sporty - 170 PS, 0 to 62 mph in 8.2 seconds and a top speed of 135 mph - but with 47.1 mpg on the combined cycle and an official CO2 rating of only 161 g/km it's also undeniably 'green' for a fully fledged hot hatch.

No wonder, then, that of the 4,000-plus Leon FRs registered in 2007 an amazing 71% (2,916 cars) were specified with the potent 2.0-litre TDI engine.

A spokesman for the SMMT said: '2007 saw fuel-efficient diesel models take a record share of the UK new car market - nearly one million vehicles. Consider this against the fact that, in 1998, diesel cars accounted for just 15.3% of new car registrations in the UK and it's clear that the drive for diesel is a very real phenomenon.

'Modern diesel engines are sophisticated power units and vastly improved on those of even ten years ago - most notably they are cleaner and quieter. A key reason for the improvement we have seen in average new car CO2 performance has been the growth of sales of diesel-engined cars.'

He added: 'Diesels are typically ten to 20% lower CO2-emitters than petrol equivalent models.'

And let's not forget that those looking for the very cleanest, greenest, diesels should also be looking to SEAT. Industry-leading new offering the Ibiza Ecomotive - with up to 88.3 mpg, just 99 g/km of CO2 and on sale now from £10,995 RRP - will be joined in the summer by the similarly green Leon Ecomotive which offers up to 76.3 mpg and CO2 of only 119 g/km.

SEAT Head of Marketing, Steve Robertson, said: 'Given the great economy and eco-performance of our TDI diesels it's not surprising so many SEAT buyers are opting for one.

'What does surprise some, though, is just what a sporty, exciting drive these engines deliver.

'Performance diesels like those in the FR range, which nimbly balance the need for improved mpg with GTI-style power, really are the best of all worlds.'