Cars being bought under the scrappage scheme have tailpipe carbon dioxide emissions 25 per cent lower than the cars they are replacing, according to new figures.
The information, released by the Department for Business, Innovation and Skills, show that cars being scrapped emit an average of 179g/km, whereas the cars being bought emit an average of 134g/km.
A regional breakdown of car sales also shows that scrappage has been most popular in the south east (18 per cent), the east of England (12 per cent), the north west (11 per cent) and south west (11 per cent).
These figures reflect a pattern that is broadly in line with national levels of car ownership - the highest participation rates for the scrappage scheme are in regions with the highest levels of car ownership.
In total, 154,927 cars have been ordered under scrappage - meaning just more than half the government's £300 million of funding towards the scheme has been used up.
The government continues to insist that it will not top up the fund once it has run out.