produce 'zero emissions' ignores the fact that most drivers use a conventional electricity supply to charge them, which has a carbon cost from burning fossil fuels. ' Fuelling the debate: The Mitsubishi i MiEV, one of three electric cars put through their paces by Which? To test its theory, Which? looked at three of the first electric cars destined to hit the UK market and put them up against three 'efficient' conventional rivals. However, electric cars are much 'greener' than diesel cars when it comes to localised emissions, as they don't emit toxic chemicals that degrade air quality. This is especially significant in cities, where the uptake of electric cars is predicted to be highest, says Which? The consumer report concludes:'While we don't agree with the car makers' 'zero emissions' claims, we can't knock their efforts to create greener cars.' Richard Headland, editor, Which? Car, said: 'We applaud car makers' efforts to create greener cars -- but we don't agree with their 'zero emissions' claims. Until more electricity is produced from renewable sources in the UK, the carbon footprint of driving an electric car may not be as small as owners think.' The report adds that electric cars are still costly - often more than double the price - despite a 5,000 taxpayer subsidy:'Electric cars offer drivers a lower-carbon output and cheaper fuelling costs, but are expensive compared with their traditional counterparts and not as versatile.' There is also a 'big question' over their second hand value as traders will