British Car Sales Drop 20 Per Cent in September Amid New Testing Requirements (Photo: Oli Scarff/Getty Images).

The UK new car market fell by 20.5 per cent in September, according to the latest data released by the Society of Motor Manufacturers and Traders (SMMT) on Thursday (4).

As many as 338,834 vehicles were registered last month, down around 87,000 on the previous year as new testing requirements continue to affect supply and distort the market.

The impact was felt across the board, with registrations by private consumers, fleets, and businesses all declining, by 20.1 per cent, 22.4 per cent and 6.3 per cent respectively.

Registrations of petrol and diesel cars also fell, while hybrids and plug-in electrics fared better, up by a modest 3.9 per cent, the SMMT said.

September’s large decline follows an unusually high August and a turbulent first eight months of the year as the market responded to a raft of upheavals, from confusion over diesel policy to VED changes and, latterly, transition to the new WLTP emissions standards.

Year-to-date performance is currently 7.5 percent behind 2017, reflecting a drop in business and consumer confidence. Over the coming months, however, some rebalancing is expected as an increasing range of new models are certified for sale and backlogs ease.

Mike Hawes, SMMT chief executive, said, “with the industry given barely a year to reapprove the entire European model line-up, it’s no surprise that we’ve seen bottlenecks and a squeeze on supply. These are exceptional circumstances with similar declines seen in other major European markets. The good news is that, as backlogs ease, consumers and businesses can look forward to a raft of exciting high-tech cars and a market keen to recover lost momentum.”

From September 1, all cars sold in the EU have to undergo a new test called the Worldwide Harmonised Light Vehicle Test Procedure (WLTP). The test measures all regulated emissions, as well as CO2 and fuel economy.

WLTP replaces the old test method and it is conducted in controlled laboratory conditions for consistency across every test and every new vehicle in every country.

However, it is conducted at faster speeds, over a longer distance and is more dynamic, with a greater range of vehicle and engine speeds, engine load, gear changes and temperatures, while also taking into account modern vehicle technology.

In addition, new cars will also need to prove their air quality credentials ‘on the road’ by passing the new Real Driving Emissions (RDE) test. This rigorous test, which takes around four days to complete, is supplementary to WLTP and uses specially calibrated state-of-the-art portable emissions measurement (PEMS) equipment.