New residual value data aims to show fleets what the best and worst used car performers will be in the future.

Analysing more than 5,000 models from 39 manufacturers, the data shows the worst performers are expected to be Daewoo, Proton and Citroen.

Prepared by Henley Autodata, the index shows brands including Audi, BMW and Mercedes-Benz leading the way in terms of residuals over three years and 60,000 miles.

The index will be published six times a year and gives full details by sector and manufacturer.

Martin Keighley, Henley’s operations director, said: "It is no surprise that the BMW X5 diesel and X3 SE came top at 62% of cost new, outperforming the average by 29%. At the other end of the scale, Proton Wira, Daewoo Nubira and the Citroen C5 struggle at just 17% of cost new – 16% below the average."