Premium used cars struggled to achieve top values at auction as hammer prices painted a “subdued” picture during January, according to the National Association of Motor Auctions (NAMA).

Despite the average used car value of £5,542 representing a 4.6% increase year-on-year (2016: £5,296) Louise Wallis, head of NAMA, suggested that larger premium diesel cars were partly to blame for rather lower than expected values overall.

Average selling values decreased by 2.7% from December’s £5,693 to £5,542 and Wallis said: “Whilst diesel cars are holding their own in general, the premium sector – particularly large premium German brands – have struggled to achieve prices that are in line with vendors’ expectations.

“This, coupled with the large volume of cars that were offered throughout the month, led to overall hammer prices being more subdued than would normally be expected in January. However, as the month progressed, prices began to strengthen.”

NAMA reported that first time conversion rates at UK car auctions had increased by 3.9% to 81.6% from December, during January.

The average mileage of a vehicle sold at auction went up by 3% to 65,726 from December, and was up just slightly by 0.6% on the same period last year.

A first time premium of -£231 was deemed a “significant” 48.1% decline on last month’s figure of £156.

Wallis said that auction activity had strengthened through the month, however.

She said: “Auction activity strengthened in January as dealers bought stock to fulfil increased demand from consumers, who are opting in favour of used cars instead of new.”