The volume of used diesel cars going under the hammer at Aston Barclay auctions reached an all-time low in Q2.

The remarketing firm's latest monthly used market report found that 42.7% of Aston Barclay’s stock in Q2 were diesel, a fall from 46% in Q1 and a sign that used diesel volumes are falling to coincide with new car fuel trends, the company said.

Diesel prices remained consistent at £8,302 in Q2, a fall of just £32 over Q1, while petrol prices fell by 1.6% (£122) to £7,447.

Martin Potter, chief customer officer at Aston Barclay, said: “Q2 has thrown up some interesting trends. Diesel volumes fell 3.3% from Q1 to Q2, but we believe that once more ex-fleet used cars reach auction diesel volumes will start to rise again.

“The overall used market is slowing down with price increases only for the right stock.

“Refurbishment levels continue to rise as vendors make their used cars as attractive as possible to increase conversion rates while buyers are handing over the hassles of improving a car’s condition to us so they arrive at the dealership retail ready.”

New tactics by car manufacturers to keep new car supply constricted could cause long-term shortages in the used market, says the Vehicle Remarketing Association (VRA).

Demand for used cars has caused prices to soar, since the start of the pandemic, with Auto Trader’s Retail Price Index highlighting a 41.5% growth in values since 2019. The average used car now retails at £17,252, according to Auto Trader.

Aston Barclay's date showed that used electric vehicles (EVs) prices, however, increased in Q2 by 11.7% (£3,289) to a new record price of £31,349.

Sale volumes also increased in Q2 by a third over Q1 showing that EVs are slowly creeping into auction and now account for 1.5% of Aston Barclay’s sales.

Used fleet prices fell by an average of 2.5% (£405) to £15,278. Aston Barclay said this is the third successive quarter where average prices were in the £15,000s which reinforces the sector’s stability.

Late and low (0-24 months) and budget (+126 months) used cars continued to buck the trend with price rises of 2.9% (£696) and 1.2% (£26) to £23,941 and £2,075, respectively.

Aston Barclay said it has also seen a marked move with vendors and buyers investing in refurbishment pre and post auction as wholesale demand and retail prices continue to slow.

It refurbished 10% of used cars in Q2 and predicts this could rise to nearer 15% as parts availability and body shop slots remain compromised.

Typically, a vendor’s £100 investment is seeing a £400 return as dealers invest in improving a car’s condition to speed up its retail sale, said Aston Barclay.