In September, automakers had to have retested all their cars to conform to new emissions regulations known as the Worldwide harmonized Light vehicle Test Procedure. WLTP is much tougher on plug-in hybrids than the previous emissions protocol. As a consequence, many plug-in hybrids are now rated as emitting more carbon dioxide than under the old standard, known as the New European Driving Cycle or NEDC.
This was devastating because suddenly it pushed many plug-in hybrids above 50 grams of CO2 per kilometer, which is the threshold needed to qualify for a raft of tax incentives. In Germany, for example, buyers would have lost access to a purchase grant of 3,000 euros.