DIESEL residual values have stopped their three-year slide which was triggered by health scares and high volumes reaching the marketplace.

Research by CAP Black Book experts shows diesel prices generally improving while the trend for petrol cars is going the other way. For instance, although a Rover 214 SLi has dropped £200 between January and April, the diesel version - the 218 SLD - has held steady.

However, that view was disputed at this week's British Vehicle Rental and Leasing Association-organised residual value seminar where Richard Lownsborough, who heads up Reg Vardy's used car buying division, claimed the diesel premium had disappeared.

Meanwhile anti-diesel stories have surfaced again with Fleet News (April 19) reporting a Mobil survey which warned that 50% of diesel vehicles could fail emission tests. But stabilising diesel prices have come too late for some. As the recession lifts, there has been a swing back to petrol. Secondhand buyers keen to avoid risks have reacted to every piece of news on emissions by interpreting the stories as a potential threat to their purchasing decisions.