BBC NEWS | Flag drag will boost fuel costs:
Patriotic drivers showing their support for England with window flags during the World Cup will pay more in fuel costs, an academic has claimed.
An average car with two flags attached burns an extra litre of fuel per hour at an average of 70mph, said Manchester University's Dr Antonio Filippone.
He also calculated that 500,000 drivers all doing the same will create 2.8m kg of carbon dioxide emissions.
The extra fuel consumption is caused by the flags creating drag.