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1. What does WLTP stand for?
WLTP is the acronym for "Worldwide Harmonized Light-Duty Vehicles Test Procedure'. This is the test procedure in the EU for exhaust-emissions and fuel-consumption values for new vehicles. This test procedure has been valid for new type approvals for M and N1 category vehicles in the European Union from 1st September 2017 and all new vehicle registrations from 1st September 2018.
2. What does NEDC stand for?
NEDC is the acronym for 'New European Driving Cycle" and is the previously applicable test cycle for determining exhaust-emission and fuel-consumption values in the EU and some countries in the rest of the world.
3. What is the difference between the measurement methods?
Whereas with the old test, the test values were based on a synthetic driving profile, i.e. New European Driving Cycle (NEDC), the WLTP cycle (WLTC) is based on data collected world-wide during road use. It therefore permits a better representation of everyday driving profiles. The NEDC is based on two driving-profile phases: urban and extra-urban.
The combined CO2 and fuel-consumption values as well as the combined pollutant emissions are obtained based on these. The WLTP driving cycle is divided into four parts with different average speeds: low, medium, high and extra high. Each part comprises multiple driving, stationary, acceleration and braking phases. In addition to the driving profile, the measuring procedure has been adapted and the current vehicle technology has been adapted with the WLTP. The specifications, e.g. at what temperature the vehicle is to be tested or what tyre pressure has to be set are more strictly defined. The new test cycle and the new test procedure are characterised by the following:
- More realistic driving cycle
- Greater range of vehicle speeds/vehicle speed types (urban, extra-urban, motorway), providing the customer with specific fuel consumption data for each speed type within the WLTP test
- Longer test distance
- More realistic ambient temperatures closer to the European average (in addition to the 23 °C test, a 14 °C test will be introduced which reflects the average temperature of the EU)
- Higher average and maximum speeds
- More dynamic and representative acceleration and braking phases
- Shorter stationary period in relation to cycle duration
- Consideration of optional vehicle equipment: Specification of CO2 values and fuel consumptions for each individually configured vehicle, taking into account additional equipment (spoiler, sunroof, tow bar etc.)
- Limitation of measurement tolerances
The specification of best and worst-case values in the WLTP in the user information reflects the possible influence of the optional equipment. It is possible to determine a vehicle specific, equipment-dependent value by interpolating between the worst and best case specification values.
4. What are the advantages of WLTP?
Due to all these changes, the WLTP provides a more realistic basis for the determination of fuel consumption and emissions data for vehicles.
The WLTP test was developed with the objective of standardising the determination of pollutant and CO2 emissions as well as fuel consumption data through its use as a global test cycle. The "core" of the WLTP test is the same world-wide. However, the European Union and other regions will adapt it to their respective road traffic regulations and requirements. There are also numerous countries who will not be introducing the WLTP, for example the USA.
5. Will WLTP put an end to the discrepancy between the values measured in the laboratory and those achieved during road driving? What is the difference between WLTP & NEDC? What difference is there between the measurement methods?
The WLTP is expected to reflect the existing road conditions more realistically than the NEDC, but will not cover all the possible variations. Moreover, each individual driver will continue to have a very personal driving style: While one person accelerates more rapidly, drives faster into bends or brakes more abruptly, another drives more defensively. Furthermore, during real operation, the weather conditions (e.g. head wind/ tailwind, different ambient temperatures), use (e.g. full loading, trailer operation), ancillary loads (e.g. radio, air conditioning etc.), altitude, inclines and the route profiles (only short trips, only motorway etc.) are additional factors which significantly affect fuel consumption.
In light of the differences with regard to driving behaviour, traffic situation and weather conditions in the individual countries, which will continue to apply in the future, the deviations between the emissions measured under laboratory and real conditions will also persist. However, because a "true" emissions and fuel consumption value does not exist in practice, it is only possible to make direct comparisons of the emissions and fuel consumption of the various models of different automotive manufacturers using measured values obtained during standardised laboratory tests.
6. What values (WLTP) are measured on the roller test stand?
During the laboratory tests in the context of the European type approval of passenger vehicles, the CO2 emissions, which bear a direct relation to fuel consumption, pollutant emissions and the energy-consumption values of alternative drives, including electrically driven vehicles are measured.
7. What is type approval?
Laboratory tests play a decisive role in the process of introducing a motor vehicle onto the EU market. Before vehicles are launched on the market, they are subjected to certain tests by a technical service in accordance with EU law. If all the registration-relevant requirements are met, a national authority issues the manufacturer an EU type approval form authorising the sale of that particular vehicle type in the EU. Every vehicle produced for the EU market is provided with a Certificate of Conformity (so-called CoC document), which, in addition to other information, includes the CO2 emission values from the laboratory test. On the basis of this document, registration of the vehicle is possible everywhere in Europe.
8. How can the motorist know what CO2 emissions the vehicle produces?
To enable motorists to make a well-founded purchase decision based on fuel consumption, car dealers and manufacturers provide the consumer with relevant information, including an indication of the CO2 emissions and fuel consumption for a passenger car, which is displayed on or near all new vehicles in the showrooms. The design of these labels is specified at a national level (and therefore differs from country to country). However, they all include the CO2 values from the standardised laboratory tests, which are also contained in the Certificate of Conformity (CoC document).
9. What is the connection between CO2 emissions and taxation?
In most EU member states, the amount of the registration tax (one-off) and/or the vehicle tax (annual) depends on the CO2 emissions of the vehicle. This taxation is based on the CO2 values obtained during the laboratory testing contained in the Certificate of Conformity (CoC document). In the UK, NEDC CO2 values will continue to be used for taxation purposes until April 2020.
WLTP is the acronym for "Worldwide Harmonized Light-Duty Vehicles Test Procedure'. This is the test procedure in the EU for exhaust-emissions and fuel-consumption values for new vehicles. This test procedure has been valid for new type approvals for M and N1 category vehicles in the European Union from 1st September 2017 and all new vehicle registrations from 1st September 2018.
2. What does NEDC stand for?
NEDC is the acronym for 'New European Driving Cycle" and is the previously applicable test cycle for determining exhaust-emission and fuel-consumption values in the EU and some countries in the rest of the world.
3. What is the difference between the measurement methods?
Whereas with the old test, the test values were based on a synthetic driving profile, i.e. New European Driving Cycle (NEDC), the WLTP cycle (WLTC) is based on data collected world-wide during road use. It therefore permits a better representation of everyday driving profiles. The NEDC is based on two driving-profile phases: urban and extra-urban.
The combined CO2 and fuel-consumption values as well as the combined pollutant emissions are obtained based on these. The WLTP driving cycle is divided into four parts with different average speeds: low, medium, high and extra high. Each part comprises multiple driving, stationary, acceleration and braking phases. In addition to the driving profile, the measuring procedure has been adapted and the current vehicle technology has been adapted with the WLTP. The specifications, e.g. at what temperature the vehicle is to be tested or what tyre pressure has to be set are more strictly defined. The new test cycle and the new test procedure are characterised by the following:
- More realistic driving cycle
- Greater range of vehicle speeds/vehicle speed types (urban, extra-urban, motorway), providing the customer with specific fuel consumption data for each speed type within the WLTP test
- Longer test distance
- More realistic ambient temperatures closer to the European average (in addition to the 23 °C test, a 14 °C test will be introduced which reflects the average temperature of the EU)
- Higher average and maximum speeds
- More dynamic and representative acceleration and braking phases
- Shorter stationary period in relation to cycle duration
- Consideration of optional vehicle equipment: Specification of CO2 values and fuel consumptions for each individually configured vehicle, taking into account additional equipment (spoiler, sunroof, tow bar etc.)
- Limitation of measurement tolerances
The specification of best and worst-case values in the WLTP in the user information reflects the possible influence of the optional equipment. It is possible to determine a vehicle specific, equipment-dependent value by interpolating between the worst and best case specification values.
4. What are the advantages of WLTP?
Due to all these changes, the WLTP provides a more realistic basis for the determination of fuel consumption and emissions data for vehicles.
The WLTP test was developed with the objective of standardising the determination of pollutant and CO2 emissions as well as fuel consumption data through its use as a global test cycle. The "core" of the WLTP test is the same world-wide. However, the European Union and other regions will adapt it to their respective road traffic regulations and requirements. There are also numerous countries who will not be introducing the WLTP, for example the USA.
5. Will WLTP put an end to the discrepancy between the values measured in the laboratory and those achieved during road driving? What is the difference between WLTP & NEDC? What difference is there between the measurement methods?
The WLTP is expected to reflect the existing road conditions more realistically than the NEDC, but will not cover all the possible variations. Moreover, each individual driver will continue to have a very personal driving style: While one person accelerates more rapidly, drives faster into bends or brakes more abruptly, another drives more defensively. Furthermore, during real operation, the weather conditions (e.g. head wind/ tailwind, different ambient temperatures), use (e.g. full loading, trailer operation), ancillary loads (e.g. radio, air conditioning etc.), altitude, inclines and the route profiles (only short trips, only motorway etc.) are additional factors which significantly affect fuel consumption.
In light of the differences with regard to driving behaviour, traffic situation and weather conditions in the individual countries, which will continue to apply in the future, the deviations between the emissions measured under laboratory and real conditions will also persist. However, because a "true" emissions and fuel consumption value does not exist in practice, it is only possible to make direct comparisons of the emissions and fuel consumption of the various models of different automotive manufacturers using measured values obtained during standardised laboratory tests.
6. What values (WLTP) are measured on the roller test stand?
During the laboratory tests in the context of the European type approval of passenger vehicles, the CO2 emissions, which bear a direct relation to fuel consumption, pollutant emissions and the energy-consumption values of alternative drives, including electrically driven vehicles are measured.
7. What is type approval?
Laboratory tests play a decisive role in the process of introducing a motor vehicle onto the EU market. Before vehicles are launched on the market, they are subjected to certain tests by a technical service in accordance with EU law. If all the registration-relevant requirements are met, a national authority issues the manufacturer an EU type approval form authorising the sale of that particular vehicle type in the EU. Every vehicle produced for the EU market is provided with a Certificate of Conformity (so-called CoC document), which, in addition to other information, includes the CO2 emission values from the laboratory test. On the basis of this document, registration of the vehicle is possible everywhere in Europe.
8. How can the motorist know what CO2 emissions the vehicle produces?
To enable motorists to make a well-founded purchase decision based on fuel consumption, car dealers and manufacturers provide the consumer with relevant information, including an indication of the CO2 emissions and fuel consumption for a passenger car, which is displayed on or near all new vehicles in the showrooms. The design of these labels is specified at a national level (and therefore differs from country to country). However, they all include the CO2 values from the standardised laboratory tests, which are also contained in the Certificate of Conformity (CoC document).
9. What is the connection between CO2 emissions and taxation?
In most EU member states, the amount of the registration tax (one-off) and/or the vehicle tax (annual) depends on the CO2 emissions of the vehicle. This taxation is based on the CO2 values obtained during the laboratory testing contained in the Certificate of Conformity (CoC document). In the UK, NEDC CO2 values will continue to be used for taxation purposes until April 2020.