Used car dealers questioned by Cap during July all reported reduced demand for secondhand 4x4s this year compared to 2006. Dealers universally attributed the sector's decline to the 'negative publicity' SUVs have received in the media.

The research also found that a typical heavy off-roader registered three years ago has lost an average 33 per cent of its value over the last two years. This compares with a decline of less than 25 per cent for an average medium-sized family car. Smaller lifestyle 4x4s, such as the Toyota RAV4, have fared even worse, with an average depreciation of 35 per cent over the same two-year period.

Alongside tougher market conditions, Cap said 4x4s had suffered because of increased fuel costs and the government's recent taxation changes in Vehicle Excise Duty. The analysts said high sales volumes in recent years had also contributed to the residual decline as the image of exclusivity enjoyed by many off-roaders had been reduced.