The values of prestige diesel cars are holding up well, and even improving in some cases, despite predictions that high volumes would seriously harm their second-hand prices.

Despite a growth of 145% to nearly 900,000 units in the premium diesel sector during the last decade, prices for diesel variants have been healthy and the difference in the prices being achieved by used petrol and diesel models have stretched in favour of diesel.

Analysis by EurotaxGlass’s found that the price gap between a 12-month-old diesel BMW 320d SE and petrol 318 SE had increased by 45%, or £2,175, since May 2003.

At new, the diesel was £1,810 more expensive, but its slower rate of depreciation meant the petrol car dropped by £365 more over the year than the diesel. The price gap between a 12-month-old Audi A4 1.9 TDI and A4 2.0 SE had also widened – by 19% to £2,150 over the same period. The diesel car’s list price was £1,490 more expensive.

The same trends are evident in the executive segment, where equivalent petrol and diesel BMW 5-series are seeing an increased differential in used prices of 35% while comparable E-class models have seen a 46% shift in favour of diesel models.

Used buyers increasingly being won over by the merits of diesel technology are the key drivers behind the strengthening residuals, as they pluck the best ex-fleet cars off forecourts.

Richard Crosthwaite, prestige car editor at Glass’s said: ‘The increased supply of diesel cars into the prestige used market isn’t having the adverse effect on values that many predicted.

‘While a large proportion of new diesel car sales over recent years can be attributed to the corporate market, it is higher levels of demand from consumers that has kept used prices firm.

Many more buyers recognise that diesel technology has moved on significantly over recent years, offering improved refinement, performance and economy, as well as strong residual values.

‘Even though some of the premiums will retreat over the coming years, diesel has become the first choice for many buyers and we do not foresee any dramatic falls in their residual values.’

How prestige diesel residual values are improving against their petrol counterparts

  • BMW 3-series: up 45%
  • Audi A4: up 19%
  • Mercedes-Benz E-class: up 46%