Volkswagen, BMW, Mercedes-Benz and Porsche are among the automakers that have halted sales of some of their plug-in hybrid cars in Europe in the wake of new emissions regulations.
The regulations, known as the Worldwide harmonized Light vehicles Test Procedure (WLTP), went into effect in the European Union this month. Under WLTP, plug-in hybrids are tested differently than under the previous regulations, known as the New European Driving Cycle or NEDC.

As a result, the effect of the fully charged battery has been reduced. That, in turn, has pushed the crucial CO2 emissions figure above 50 grams per kilometer. The cars lose tax benefits offered in many countries to ultralow-emissions vehicles.

In Germany, many plug-in hybrid models have fallen out of the category where they qualified for the 3,000-euro (about $3,500) subsidy, said Matthias Schmidt, an analyst for Sweden's AID automotive research company. In most cases, automakers will need to fit a bigger battery into the vehicle to keep the tax benefits, Schmidt said.

Automakers have to decide whether the extra cost to fit a bigger battery is worth the incentives given.

VW has stopped sales of the midsize Passat GTE, Europe's No. 2-selling plug-in hybrid. A VW spokesman said the model will not be sold again until next July, when an update for the Passat range is due.

VW also has stopped selling the compact Golf GTE, Europe's No. 4-selling plug-in hybrid. The company did not give a date for its return.

The VW spokesman said its plug-in hybrid models were at the back of the line for WLTP testing behind more popular conventional gasoline and diesel models. "There is a bottleneck with the testing," he said. "We have to get priority for highest-volume models."

Porsche has pulled sales of its plug-in hybrid Panamera sedan and Cayenne SUV. "We will not start taking orders again until the cars are being built, the timing of which has not yet been confirmed," a spokesman said.

Plug-in hybrid versions accounted for 69 percent of Panamera sales in western Europe in the first half, AID figures show.

Mercedes currently has no plug-in hybrids available to order but will start selling them again within the next two months, starting with the S-class and E-class models. The C class is not due until next year, a spokesman said. All will record under 50g/km of CO2, he said.

Mitsubishi meets rules

Mitsubishi Europe, meanwhile, has overhauled its Outlander plug-in SUV, Europe's best-selling plug-in hybrid. The SUV has CO2 emissions of 46 g/km under WLTP, Mitsubishi said.

"As a result, it will still be eligible for numerous incentives and entry to low-emissions zones throughout the world, including Europe," Mitsubishi said in a statement.

The new Outlander plug-in switched to a 2.4-liter gasoline engine from a 2.0-liter engine and increased the size of the battery to 13.8 kWh from 12kWh.

Volvo, maker of the third-best-selling plug-in hybrid vehicle with the XC60 crossover, sells its plug-in hybrids with WLTP certification — but its vehicles are rated above 50g/km of CO2.

BMW is working to switch its plug-in hybrids over to WLTP. The company says the 530e sedan is available to order with emissions below 50g/km. The BMW 225xe Active Tourer minivan also can be ordered but with a CO2 figure of 57g/km, which is above the critical threshold.

BMW has said its new X5 large SUV will include the xDrive 45e plug-in hybrid with a beefed-up battery to increase its electric-only range to 80 km (50 miles) from 31 km (19.2 miles) and record a CO2 figure of 49g/km. It will arrive in 2019.

Tough tests

Plug-in hybrids must complete the WLTP test several times, Germany's VDA said. "Roll-out of the WLTP signifies a major change for plug-in hybrid vehicles," it said on its website. The vehicles are tested with a full battery, then the test is repeated until the battery is empty, when they are tested again.

"The CO2 value is then calculated as the ratio of the electrical range to the total range," the VDA said.