Used diesel car values have hit a two-year high with strong interest in them continuing from trade buyers and their retail customers, says Aston Barclay's 2017 Market Insights report.

The remarketing company says average diesel auction prices increased £601 since Q1 2016 to £8,829 in Q4 2017, while ex-fleet diesels reached a two-year high rising 11.4% to £10,076 in Q4 2017, helped by a fall in average age and mileage to 41.1 months/54,415 miles.

At the same time, average used petrol prices increased by £426 to £4,011 from Q1 2016 to Q4 2017, while ex-fleet petrol prices stagnated over the 24-month period at around the £7,250 mark.

Martin Potter, Aston Barclay’s group operations director, said: “2017 delivered a stable used car market, with diesel demand and prices remaining strong.

"The continued fall in new car sales will see fewer dealer part exchanges entering the used market in 2018.

"However, higher used car volumes are likely to balance this shortfall as stock comes back from the peak new car sales years of 2013 and 2014."

Generally, 2017 saw a strong used market only faltering in Q2 partly due to dealers pushing new car sales into March as a reaction to 1 April VED changes.

This retail activity meant trade buyers had greater used stock choice in April and May earlier than usual which contributed to a Q2 average price fall to £6,485 from £6,609 in Q1.

Prices picked up again finishing Q4 at £6,991, just £174 shy of the Q4 2016 average market price (£7,165).

Alternative fuelled vehicles (AFVs) are slowly growing in volume at auction (from 2-3% of all cars sold) with the higher average mileage versus diesel (64,700 v 54,415 miles).