Energy savings overestimated
 

BBC news item

Why am I not surprised.

So you buy a car that is energy efficient, then you drive it around more because you can afford to buy more petrol, class! As many have said all along, the tax should be on the fuel. A litre of petrol produces a set amount of CO2. A small car driven 60,000miles a year will produce more emissions than a gas guzzler only brought out for short trips at weekends.

The same with electricity. All the money you save from low energy bulbs gets ploughed back in to buying a dishwasher or something, so your carbon footprint isn't actually reduced.

And the fact you may have a less efficent car so you buy a new one - but they don't factor in the CO2 etc from building a new car when there's nothing wrong with your old one.