Volkswagen has added its two seven-sweaters to its ever-growing Bluemotion line-up. The range is super-economical on fuel and low on carbon dioxide emissions.

Newly introduced versions of VW’s mid-size MPV, the Touran, and the full-size Sharan promise overall up to 52.3mpg and 47.1mpg respectively and CO2 emissions of 144 and 159g/km. Like others in the range, these models use regular diesel engines. VW’s engineers improve economy and reduce emissions by making minor changes to the engine, gearbox, body styling (so that it slips through the air more cleanly) and by fitting easy-roll tyres.

The Touran uses a 105bhp, 1.9 diesel engine that also powers the Golf Blue motion, while the Sharan harnesses a 2.0-litre, 140bhp diesel.

These Bluemotions have seven individual seats, air conditioning, six airbags, anti-lock brakes and a CD radio. Both models are on sale now, and prices are from £16,725 for the Touran and £21,290 for the Sharan.

VW is the first car maker to sell a full range of ‘eco-friendly’ cars in this way. And work is already advanced on second-generation Bluemotion models. The company is already promising a version of the Golf for next summer that will return 74mpg and pump out just 99k/km of CO2 – that’s low enough to exempt it from road tax.