The car market in Europe has seen the largest drop in monthly sales of the decade so far, with the month of September experiencing a 23.4% drop year-on-year from the impact of the recently introduced WLTP (Worldwide Harmonised Light Vehicle Test Procedure) emissions standards.

According to industry analysts JATO, 1.12 million vehicles were registered across Europe last month, which marked a drop of 343,000 units compared to September last year. This decline was expected due to hurdles faced by automakers in getting their models ready to meet the new, more stringent WLTP tests, while JATO noted that just 57% of previously sold models could currently meet the new regulations, according to Autocar.

Overall European sales are still up 2.3% year-on-year, and registrations in the month of August saw spikes as automakers worked to clear existing stock ahead of WLTP coming into effect on September 1, Autocar noted.

“We will continue to see registrations decline so long as a large portion of the market’s versions remain unavailable under the new test conditions. The big question now is how long the drop will last, which will depend on how long it takes car makers to homologate the models they want to keep on the market,” said JATO analyst Felipe Munoz.

The new WLTP regulations proved particularly challenging for the Volkswagen Group, and as a result ceded the sales lead to the PSA Group, comprising Peugeot, Citroën, DS and Vauxhall and Opel. This would mark last September as the first month in eight years that brands from the Volkswagen Group failed to top the European sales charts, the report said.

The PSA Group’s newfound market lead can also be attributed to particularly strong performance from Vauxhall and Opel last month, with 80,920 registrations – just ahead of Ford, at 80,813 units – bringing the brands to the top of the sales chart, despite September year-on-year sales sustaining a 12% dip. Long-time leader Volkswagen saw a 53% drop to 74,469, with the decrease especially marked in Germany. Audi followed the same downward trend with a 60% sales drop.

Europe’s perennial favourite, the Volkswagen Golf struggled to the tune of a 71% drop in registrations to 14,968 units, replaced by the Vauxhall Corsa as the new market leader with 24,752 units registered, representing a 5% increase. The Ford Fiesta also did well, recording 22,478 registrations – a 20% increase, putting it second in European sales for this period.