With the European Union pushing to mandate a blanket 130g/km average fleet limit for CO2 emissions per car brand by 2012, Porsche has made waves this week by saying that if such a proposal was accepted, it could be forced to close its doors.

That won't happen, of course. The company is just too big and influential for that these days; remember that it's the majority shareholder of Volkswagen, Europe's largest car-maker, and parent to Audi, Bentley, Lamborghini, Seat and Skoda no less. But chairman Wendelin Wiedeking has begun to ramp up his opposition to the controversial EU proposal, which he says discriminates against makers of more overtly sporty cars.

His suggestion – and it is a good one – is a graduated plan whereby each class of car would be given a different CO2 limit to meet, with smaller, low-powered cars set lower limits than larger, more powerful cars.

It makes sense, though I can see problems in trying to classify various cars; is a Mercedes-Benz R-class a luxury sedan or an MPV, for example? As Wiedeking pointed out, "it is just not technically possible for a car like a 911 to meet the same levels of CO2 mandated for a Polo."