The test protocol is highly reproducible with a margin of error of just ± 3%. The roughly one thousand results not only match internal PSA data from their customers but also the information uploaded by drivers themselves onto public web-based data sets such as Germany's www.spritmonitor.de. The Spritmonitor results are within ± 0.2 litres per 100km driven.
The development of the real-world fuel consumption test protocol commenced in late 2015 and has involved a substantial testing effort with the objective to cover 80% of the volumes sold by Peugeot, Citroën and DS brands, both for passenger cars and light commercial vehicles.
The tests performed on passenger cars reveal an average fuel consumption of 5.8 litres/100km, and confirm an average gap with official type approval figures of 1.74 l/100 km. The results that show PEMS* tests provide a robust, representative and repeatable basis for measuring real-world fuel economy and CO2 emissions. The results are accurate within 0.3 l/100km.
The measurements carried out under the Protocol provide some relevant information:
- The tests show that on-board computer gives reliable information to the driver.
- A diesel car consumes 1.5 l/100km less than a gasoline one.
- In urban conditions, the gap between certification and real-life data is equal for diesel (2.4l/100km) and gasoline (2.5 l/100km) when expressed in litres/100km but is higher for diesel (53%) compared to gasoline (42%) when expressed in percentage.
- A diesel car’s efficiency is less sensitive to driving style than that of a gasoline car.
- Fuel consumption is lower on cars with a manual gearbox than with an automatic transmission (- 0.4 l/100km).
For PSA, the purpose of this Protocol was to give full and transparent information to customers regarding the real-world fuel consumption of Peugeot, Citroen and DS models.
The measurements obtained on the 60 models make it possible to estimate the consumption in real-world driving conditions of more than 1,000 versions of Peugeot, Citroën and DS vehicles. For each model, the estimates have been made using the same engine and gearbox, plus three variants: body type, trim level and tire size.
Peugeot, Citroën and DS brands offer their clients the possibility to check their average consumption in real-world driving conditions by logging onto their respective websites. A web-based application allows them to view this data for their model by entering its characteristics (body type, trim level, engine, gearbox and type of tyres).
Customers can also estimate their own consumption based on the actual use of their vehicle (number of passengers, load, driving style, etc.). The application is now available on the brands’ websites in 12 European countries.
Gilles Le Borgne, Executive Vice President, Quality and Engineering, for the PSA Group explained: "The Protocol developed with T&E and FNE is a reliable response to the questions our customers may have concerning their consumption. They can access comprehensive and transparent fuel consumption data audited by Bureau Veritas. We will add the first figures for NOx emissions by the end of 2017."
Greg Archer, Director of Clean Vehicles at Transport & Environment (T&E), said: “These real-driving tests show that it is perfectly possible to achieve CO2 emissions and fuel consumption figures almost identical to those obtained by drivers on the road. But real-driving tests are only part of the solution to the emission cheating scandal. The upcoming EU decisions on how and who approves cars for sale will be key to ensuring the system of testing and approving cars is independent and rigorously enforced."
Philippe Lanternier, Executive Vice-President, Corporate and Business Development at Bureau Veritas added: “The protocol has proven to be extremely reliable for real-world fuel consumption tests. We are confident this extensive experiment can be successfully replicated to effectively measuring NOx emissions. This new step will contribute to further increase the reliability of automotive tests and measurements.”
* PEMS : Portable Emissions Measurement System
Download the full technical report here: Protocol technical insights