Statutory test methods for consumption, emissions and pollutants.
In 1992, the New European Driving Cycle (NEDC) was introduced. This procedure was used to determine the fuel consumption and emission values of vehicles.
In September 2018 a new driving cycle called Worldwide Harmonized Light Vehicles Test Procedure (WLTP) was introduced to replace the NEDC. This laboratory test is also supplemented by an emissions test that measures pollutants directly on the road: Real Driving Emissions (RDE).
These test procedures enable consumers to better estimate their vehicle's fuel consumption and emissions.
WLTP is based on an approximation of the test conditions to real-world circumstances, which means that the values determined will also have a greater relevance to reality. Among the changes this involves are redefined, significantly stricter test conditions and higher speeds together with a substantially longer test duration (30 instead of 20 minutes).
To obtain a more precise determination of CO2 emissions, this test procedure includes not only standard equipment – as was previously the case – but also all optional equipment of a vehicle. This produces two values for each type of vehicle: the lowest and highest possible standard consumption value according to aerodynamics, weight and rolling resistance.
Thanks to WLTP, you are able to better assess a vehicle's consumption and CO2 emissions. In the case of a specific vehicle configuration, the individual standard value will be indicated directly.
In spite of the great accuracy, deviations are of course also possible with this test procedure. Everyday consumption and CO2 emissions continue to be subject to the different conditions of topography, climate and personal driving technique. The traffic situation, the current load carried and the use of devices such as the air conditioning system are further influences on the consumption of a vehicle.
One thing is clear: the test conditions are more realistic than ever before, which means that higher fuel consumption and CO2 values as well as lower ranges for electric vehicles can be expected on paper. However, this will not have any adverse effect on the real fuel consumption or range. Furthermore, the BMW Group is always working on new technologies in order to improve consumption and range.
The BMW Group has already transitioned to the new test procedure, having prepared its product portfolio step-by-step with new vehicles, new engine versions or technical revisions. This ensured that all vehicles within the entire fleet of the BMW Group comply with the applicable legislative framework at all times.
From September 2018, all manufacturers were obliged to test in accordance with WLTP for vehicles sold in the EU as well as in Switzerland, Turkey, Norway, Liechtenstein, Israel and Ireland.
In December 2020, all countries that adopted the EU legislation for vehicle registration had to indicate and communicate WLTP values for all vehicles.
The EU exhaust emissions standard defines the valid limits for exhaust emissions such as nitrogen oxides and particulate matter within the EU. The limits vary according to engine and type of vehicle. For the benefit of climate protection and air quality, the limits undergo increasing intensification, thus confronting automobile manufacturers with new challenges.
Disclaimer: Not all transition dates to WLTP communication are already finalised as they depend on the national legislation of each country. However the BMW Group will provide their customers with information as soon as possible. For more information on when your country will transition to WLTP please contact your BMW service partner.
As a matter of principle: BMW Group vehicles comply with respective legal requirements. Confirmation of this is provided by the results of relevant official investigations at the national and international level.
Specific differences between the old and current test procedure:
| Test conditions | NEDC | WLTP |
|---|---|---|
| Test duration | 20 min. | 30 min. |
| Test distance | 6.8 miles | 14.6 miles |
| Time spent stationary | 25% | 13% |
| Test phases | Urban, extra-urban, (combined) | Low, Medium, High, Extra high, (Combined); (plus “City” for electric vehicles and vehicles with plug-in hybrid drivetrain) |
| Speed | Average: 21.1mph, Maximum: 74.6mph | Average: 29mph, Maximum: 81mph |
| Start temperature | 20-30°C - Cold engine start | 14°C (tested at 23°C corrected for 14°C) - Cold engine start |
| Special equipment options | Not taken into consideration. | All equipment options are considered in terms of their influence on aerodynamics, weight and rolling resistance. |
Restriction of pollutant values on the road.
In addition to WLTP, RDE is also compulsory for all vehicle manufacturers in the EU as well as in Switzerland, Turkey, Norway, Liechtenstein, Israel and Ireland since 2018. In these RDE tests, the pollutant emissions such as particulate matter and nitrogen oxides (NOx) are measured directly on the road. This method determines average emission values that can be expected during everyday driving.
In order to further reduce these pollutant values, the BMW Group employs various technologies for reducing exhaust emission in its models.
The BMW BluePerformance measures, for example, reduce the emission of nitrogen oxides in diesel engines. The BMW Group is using devices known as nitrogen oxide (NOx) storage catalytic converters in order to reduce nitrogen oxide emissions. In addition, and depending on the model, Selective Catalytic Reduction (SCR) with AdBlue® – a urea solution – converts up to 90% of the nitrogen oxides into water vapour and similarly harmless nitrogen.
The BMW Group was the first manufacturer to introduce the combination of NOx storage catalytic converter and SCR system into series production.
Since 2006, diesel vehicles have additionally been equipped with particulate filters as standard in order to reduce particulate matter. In petrol-engine models, too, special particulate filters are gradually being introduced.
In this way, the BMW Group is able to comply with the low threshold limit values of the EU6c exhaust emissions standard, which has been compulsory for all new vehicles since September 2018. The EU6c exhaust emissions standard prescribes lower particulate limits for petrol-engine vehicles compared to EU6b. The same limits apply for diesel-engine vehicles within the cycle for both EU6b and EU6c.
The milestones.
A vehicle’s consumption and emissions depend on driving style. This is why driving data has been compiled for WLTP around the world. This data has been used to define 4 representative phases with different average speeds: low, medium, high and extra high. Within each of these phases, there are different intensities of acceleration, braking and stopping in order to depict situations with a relevance to everyday driving style. The combination of these phases then results in the driving cycle.
The BMW Group has already begun transitionining to the new test procedure and is preparing its product portfolio step-by-step with new vehicles, new engine versions or technical revisions. This ensures that all vehicles within the entire BMW fleet comply with the conditions of their respective legal framework at all times.
As a matter of principle: vehicles of the BMW Group comply with the respective legal requirements. The relevant results from national and international official investigations confirm this.
Introduction of WLTP means that the fuel consumption and CO2 values indicated will approximate those in real-world operation. Irrespective of this, taking into account individual special equipment in WLTP additionally leads to more realistic values as they are based on your personal vehicle configuration. At the same time, however, more realistic values will also mean higher consumption and CO2 values for vehicles with combustion engines and a lower electric range for electric vehicles (including plug-in hybrids). Depending on national legislation, higher CO2 taxes may result.
The abbreviation RDE stands for "Real Driving Emissions". This is a procedure for determining pollutants such as nitrogen oxides (NOx) and particulate matter. The crucial feature is that measurement takes place on the road under realistic driving conditions and not in the laboratory. A device known as a Portable Emissions Measurement System (PEMS) is attached to the exhaust of the test vehicle for this purpose.
Euro 6 is the name of the current exhaust emission standard for pollutants. It defines lower maximum values for particulate matter and nitrogen oxide emissions than EU5. Since September 2018*, the EU6c emission standard has been compulsory, and in comparison to EU6b it specifies even lower limits for the content of particulate matter in petrol-engine vehicles. The same threshold limit values apply for diesel-engine vehicles within the cycle for both EU6b and EU6c. EU6d-TEMP from September 2019* and EU6d from January 2021* will again slightly lower the threshold limit values for the number of particles and nitrogen oxides in line with RDE.
*Applies to new vehicles. New vehicle types will each be subject to the new exhaust emission standards 1 year earlier.
So that the exhaust emission values of a vehicle can be further reduced, liquid ammonia, called AdBlue®, is fed into diesel engines' exhaust system. Selective Catalytic Reduction (SCR) with AdBlue® reduces up to 90% of the nitrogen oxides. What remains is water vapour, nitrogen and CO2. What remains is water vapour, nitrogen and CO2.
BMW uses BluePerformance technology to reduce the nitrogen oxide emissions of its vehicles even further. This technology allows the emissions performance of the diesel engine to be further optimised. In addition to the diesel particulate filter and NOx storage catalytic converter, in some models the SCR catalytic converter (SCR = Selective Catalytic Reduction) with AdBlue® injection guarantees a significant reduction in nitrogen oxides contained in the exhaust gases.
The particle filter is a measure for reducing particulate matter present in diesel engines and petrol engines.
As electric and hybrid vehicles are used mainly in urban areas, WLTP provides, in addition to the four phases of low, medium, high and extra high, a separate 5th phase for them – namely the City Phase. This combines the speeds of the phases that best reflect the motoring situation in urban areas: low and medium. This enables more realistic indications of range to be given.