Comparing “real-world” fuel economy and emissions data with “official” numbers from major automakers reveals striking differences, according to Nick Molden, CEO of Emissions Analytics.
The UK-based company has tested more than 1,000 cars on the road in Europe and the US over the past four year in real-world driving situations.
Molden says the push for real-world emissions data, which is growing in part because of the Volkswagen emissions scandal, could spark reductions in vehicle emissions.
Molden shared results from his company’s research during a presentation at the Automotive Testing Expo this week at the Suburban Collection Showplace in the Detroit suburb of Novi.
“We started testing tailpipe emissions on the road in 2011,” he said. “Based on our findings, we’ve felt strongly that this is the only way to truly understand real-world performance.”
Molden said a more uniform way of testing new-model emissions and fuel-economy performance will soon be implemented in Europe with the real driving emissions (RDE) procedure that will more closely align lab testing with real-world results.
He noted that emissions from European cars are on average four times the regulated NOx limit when measured in real-world driving, and CO2 is on average 31 percent over the limit.
“For car buyers, this means that fuel economy on average is one quarter worse than advertised,” Molden said. “This matters, even if no illegal activity is found. These differences may well be explained by limitations in the official system, rather than through illegality.”
Molden said that RDE tests can be especially helpful in designing effective test cycles that eliminate discrepancies between lab testing and results from on-road testing.
Late last month the EPA sent a letter to vehicle manufacturers notifying them that the agency is adding to its confirmatory testing additional evaluations designed to look for potential defeat devices, like the software VW used that allowed almost 500,000 of its diesel-engine cars to cheat emissions testing for certain air pollutants.