The after effects of the Volkswagen diesel emissions scandal could spell bad news for plug-in hybrids, former Fiat powertrain researcher Rinaldo Rinolfi told Automotive News.
Calls for more real-world emissions testing have come about in the wake of the VW diesel emissions scandal, which saw the German automaker easily skirt emissions laws by fitting their cars with a special cheat device that would activate in lab tests. Plug-in hybrid vehicles won’t score well on these real-world emissions tests, Rinolfi claims, as they will show a more realistic reflection of their fuel economy ratings.
“Under the current NEDC (New European Driving Cycle) you test the car twice, once with the hybrid battery connected and then once without,” Rinolfi told AN. “Depending on the strength of the battery, the first cycle can be run without using the internal combustion engine, resulting in zero fuel consumption and emissions. Since the homologation value is the average of the two tests, you basically halve what the internal combustion engine burned and emitted in the second test, resulting in incredibly low values.”
Because the first electric-only cycle won’t be run in the real-world tests, the emission ratings of plug-in hybrids is expected to be about 30 to 40 percent lower than what it is now once the changes are implemented. Hybrids are good in stop-and-go traffic but struggled during high way driving, so how well hybrids rate in these tests going forward will ultimately depends on the weight of stop-and-go driving in the revised rules, Rinolfi said.
Fiat Chrysler recently debuted its first mass-market plug=in hybrid vehicle, the Chrysler Pacifica Hybrid. The van uses a 3.6-liter V6 engine and an electric motor with a16-kWh battery to achieve a combined rating of 80 eMPG, a figure that is reached by combing the vehicle’s actual MPG with its 30 miles of electric range. Under real-world testing, a vehicle like the Pacifica hybrid would receive a much lower average MPG rating.