The newly implemented WLTP emissions test has shaken up the European car market, leaving manufacturers rushing to certify models and dropping variants from their ranges.

WLTP (short for Worldwide harmonised Light vehicles Test Procedure) replaced the New European Driving Cycle (NEDC) test, which had been heavily criticised for not reflecting real-world conditions, on 1 September.

What does it mean for the consumer? In theory, cars that are sold today will be no more or less efficient in the real world than they were before. Many buying from dealer forecourts today will still find cars that have only been tested under the old regime, but even those that have been tested under WLTP rules should return near-identical figures. As our research shows (see right), that is not the case for a lot of cars.

The changes to the test are simply to provide claimed figures that are more representative of the MPG and emissions the cars will produce in normal use. The tests will also provide a rating for the car’s particulate emissions, such as nitrogen oxide. 

What will affect buyers, though, is that several car makers have taken models that won’t conform to the new standards off sale. For example, BMW stopped production of the M3 sports saloon early, while Jaguar has slimmed down the XF range and removed petrol XJs entirely. Subaru has also ceased selling diesel vehicles altogether.

Some models, such as the Volkswagen Golf R, have had their power output reduced to drop tailpipe emissions. Other changes are temporary. For example, Skoda has ceased selling some Octavia and Rapid variants until at least October. Production delays are also on the cards, causing particular problems for the VW Group. Seat sources estimate a four-to-eight-month wait for bestselling models, with similar delays for VW.

Buyers of all brands in the UK are advised to check with their dealer to see which model variants are still on sale, and which will face heavy delays.

Many car manufacturers are testing their models under the new WLTP rules but then converting them back to 'NEDC equivalent' figures, which they are allowed to do by law until 2020 when a new taxation system is brought into place. Autocar has obtained a small handful of the un-converted WLTP figures, and the contrasting changes from the old NEDC figures can be seen below. More figures will be revealed in the coming weeks and months, showing more models with stark changes to their published economy.

WLTP winners and losers:

Biggest Change

BMW X5 30d SE: Before (NEDC) 47.9mpg, 156g/km | Now (WLTP) 40.9mpg, 183g/km

Jaguar XF Sportbrake 2.0d: Before (NEDC) 62.8mpg, 118g/km | Now (WLTP) MPG tbc, 143g/km

Range Rover Evoque 2.0 eD4: Before (NEDC) 65.7mpg, 154g/km | Now (WLTP) 48.7mpg, 154g/km

Volvo V40 R Design Pro D2: Before (NEDC) 78.5mpg, 94g/km | Now (WLTP) 58.9mpg, 126g/km

Mercedes GLA 200d SE: Before (NEDC) 68.9mpg, 108g/km | Now (WLTP) 51.4mpg, 147g/km

Smallest Change

Audi A1 1.6 TDI S-Line: Before (NEDC) 76.3mpg, 98g/km | Now (WLTP) 74.3mpg, 100g/km

VW Passat 2.0 BiTDI: Before (NEDC) 51.4mpg, 144g/km | Now (WLTP) 49.6mpg, 150g/km