Parking permit charges based on the length of the car are to be introduced in Norwich from next month.
The controversial measure ends the current flat-rate of 16 per year for a motorist to park outside their hous in a bid to free up road space and reduce emissions by encouraging residents to choose smaller, greener cars.
Under the new scheme, any car over 4.45 metres in length counts as 'long'. That includes the Ford Mondeo and BMW 3 Series.
Owners of these models will now have to pay 30 a year to park outside their house.
Mid-sized cars of between 3.92 metre and 4.45 metres will pay 22 and drivers of cars of under 3.92 metres, such as a Volkswagen Lupo, will continue to pay 16 a year.
However, many modern superminis such as the Vauxhall Corsa are too long to fit in the small size band.
Motoring groups have questioned whether such a system will really encourage drivers to choose cleaner cars.
'Focusing on length confuses the issue,' said the RAC Foundation's research development manager, Elizabeth Dainton. 'There are long cars which have very low carbon dioxide emissions. This system discriminates against drivers who are just trying to get their family from A to B.'
Owners of petrol-electric hybrids such as the Toyota Prius are exempt, as are electric vehicles and those which run on LPG (Liquefied Petroleum Gas).