A fifth of car fuel-efficiency savings are eroded by increased driving

A fifth of car fuel-efficiency savings are eroded by increased driving. Around a fifth of the energy-saving benefits of fuel-efficient cars are eroded because people end up driving them more, according to a study into British motoring habits over the last 40 years. Using data from 1970 to 2011, energy experts at the University of Sussex found a long-term 'rebound effect' among British car-drivers of around 20 per cent. Published in the February issue of the journal Energy Economics , this is the first estimation of this so-called 'rebound effect' - a term used to describe the increased consumption of cheaper energy services - for car travel in Great Britain. Nearly all previous studies have focused on US motorists and so only provide limited insights for British policy makers due to the differences in population densities and car use between the two countries. Dr Lee Stapleton , Research Fellow in the University's Centre on Innovation and Energy Demand , said: "Improvements in fuel efficiency should lead to reductions in fuel consumption. But since improved fuel efficiency makes driving cheaper, some of the potential fuel savings are 'taken back' through increased driving.