To many people, the gas guzzling, road hogging, bullbar-brandishing four wheel drive or sports utility vehicle has long seemed fair game. What are they doing, clogging up the streets of our inner cities? Have their drivers somehow missed the turning to rural Ambridge?

In the United Kingdom, the Independent newspaper has called them “Enemy of the people.” Andrew Simms, policy director of UK think tank the New Economics Foundation, has dubbed them “Satan's little run-around.” Less derogatory nicknames include include “Chelsea tractors” and—in Newcastle upon Tyne—“Jesmond tractors,” because of their popularity in chic, urban areas—particularly, as the stereotypers would have it, among the so called yummy mummies or young stylish mothers. London mayor Ken Livingstone has called those who take their children to school in four wheel drive vehicles “complete idiots” and last week proposed increasing the London congestion charge to £25 for “environmentally damaging” vehicles, which would include the larger four wheel drives.

It seems that almost no one, apart from their owners and manufacturers, has a nice word to say about these behemoths. How marvellous, then, must the BMJ's recent study have seemed, confirming as it did all the prejudices that critics hold about Chelsea tractors (BMJ 2006:333: 71-3 and …