PSA/Peugeot-Citroen gave journalists a glimpse of how real-world emissions testing works as part of its effort to restore consumer confidence that has been damaged by Volkswagen Group's emissions-cheating scandal.
Starting in June, PSA will publish real-world fuel economy/CO2 emissions figures alongside official laboratory test figures for 30 of its models.
The automaker says its on-road testing method can win back trust by giving customers a much clearer idea of how much fuel their cars use during everyday driving.
To show other automakers and EU regulators that it could be a viable test, PSA invited journalists to drive a route comprising one-third rural, one-third urban and one-third motorway sections.
My task was to drive a Peugeot 308 with a 1.2-liter three-cylinder gasoline engine along a 90km route PSA devised around the Paris suburb of Poissy. If my driving style fell within the test parameters, my figure would be added to create an average for that model.
Tape on the tire valves and the hood showed that the car has been checked by certification company Bureau Veritas. A bulky PEMS (portable emissions measurement system) was fitted to the trailer hitch at the back of the car. PSA says there's no way the car's engine control unit could know that it was being monitored.
I drove around the pretty suburb of Poissy and past PSA's factory before heading out to the rural and motorway sections and returning back.
How did I do? PSA interrogated the PEMS device and established that the car's average fuel usage was 7.6 liters per 100 km (37 UK mpg) against an official figure of 4.6 l/100km (61 UK mpg). That's 40 percent worse.
PSA says its figures show a 30 percent drop on average compared with official results. Indeed, my figure is discounted because I'm judged too aggressive on the pedals during the rural and urban sections compared with their customer data. They might be right. PSA says overall its figures are broadly comparable those posted by owners on independent websites such as Spritmonitor.
Currently, new cars in the EU are tested in laboratories under the New European Driving Cycle (NEDC). The test is outdated and detractors argue it's too easily gamed by automakers that stand to lose out financially if their car does badly. No normal driver can repeat the lab figures on the road.
Starting in September 2017, the test for EU type approval switches to the more realistic Worldwide harmonized Light vehicles Test Procedures (WLTP), but cars will still be tested for CO2 emissions in labs rather than on the road under the new procedure. The road part of the WLTP tests covers Real Driving Emissions for toxins such as NOx rather than CO2.
VW's diesel emissions scandal is a separate issue to CO2 emissions. VW engineers devised a software cheat in the cars' engine management systems that turned on pollution control systems during lab tests for NOx emissions but turned them off when the car was not being tested.
PSA says that it is possible to test for both CO2 and NOx emissions on the road with the protocol it devised with Brussels-based environmental lobby group Transport & Environment.
It's a good idea. Customers want to know how much a new car will cost them in fuel bills and government agencies want a more accurate figure to establish CO2 emissions. Of course it's still possible to cheat, but PSA's test comes closer to capturing the real figures.