Porsche - WLTP testing

WLTP testing

WLTP testing

The Worldwide Harmonized Light-Duty Vehicles Test Procedures (WLTP) are the replacement for the New European Driving Cycle (NEDC) tests which were in use until 1 September 2018. Both the old and the new tests are designed to measure exhaust emissions and fuel consumption. The WLTP testing cycle is based on real-time data collected world-wide during road use – giving a better representation of everyday driving profiles. Every vehicle produced for the EU market is provided with a Certificate of Conformity (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.

Questions on technical basics

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 the exhaust-emissions and fuel-consumption values for new vehicle types applicable from September 2017. This test procedure has been valid for new type approvals for M and N1 category vehicles in the European Union from 01.09.2017 and for all new vehicles from 01.09.2018.

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 real-time 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 to the current vehicle technology 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 track
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, trailer hitch etc.)
Limitation of measurement tolerances
For a mandatory specification of the worst case (vehicle high) values, it is possible to determine a best case (vehicle low) and to interpolate the vehicle-specific, equipment-dependent 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 US.

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).

Customer-relevant questions

1. According to the WLTP method, the results of the CO2 test will be higher. Does this mean that my fuel consumption has increased?

In practice and with otherwise unmodified technology, the actual fuel consumption will not change. For one and the same vehicle, the WLTP test will result in higher CO2 and fuel-consumption values than the NEDC test for the simple reason that the driving profiles and the measurement conditions (maximum speeds, dynamics, etc.) differ between the two test cycles. This means that the WLTP is more representative of today's road traffic conditions than the NEDC. The CO2 value according to WLTP therefore corresponds more closely to customer expectations owing to the changed measurement methods.

2. Will the WLTP test affect the cost of my vehicle tax?

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. The new test procedure will probably be taken into account for the new vehicle taxation from 01.09.2018. Adaptation of the CO2 taxation is the prerogative of the individual EU member states and is therefore regulated in the applicable national law.

3. How can it be that a passenger car suddenly has two different CO2 values?

Before the start of the transition period from NEDC to WLTP, which begins from 01.09.2017, only the CO2 values measured according to the NEDC test continue to apply for all registered vehicles.

When a new car is type approved after 01.09.2017, the official Certificate of Conformity for the vehicle contains both the CO2 emissions values according to the new laboratory test (WLTP) as well as the NEDC values simulated using the correlation tool or actually measured using the updated NEDC test.

Accordingly, after 01.09.2017, when the change from the old NEDC test to WLTP is complete, you may find different CO2 values in the CoC document for your vehicle. From 01.09.2018, both the NEDC as well as the WLTP CO2 values must be indicated for all new vehicles. From 2021, it is expected that only the WLTP value will be indicated in the CoC.

Indication of the WLTP values to the customer has not yet been scheduled and will be determined on a country-to-country basis.

4. When will the changes enter into force?

The WLTP legislative package has been fully valid since 27.07.2017. This means that from 01.09.2017, new vehicle types will be type-approved in accordance with WLTP. From 01.09.2018, all new vehicles (new registrations) will be type-approved according to WLTP. There are legal provisions in place for end-of-series vehicles, which make it possible to stock a limited number of vehicles approved according to the old procedure and to sell these by 31.08.2019.

5. Why has Porsche not indicated any WLTP values to date?

Porsche is unable to indicate WLTP values, because no new Porsche model has been type-approved in accordance with the new procedure. Moreover, the legislation has not yet made use of the WLTP values in customer communications compulsory. Until a change to the “PKW Energieverbrauchskennzeichnungsverordnung” (energy labelling consumption regulation for cars), the specification of the NEDC values, however, is obligatory.

6. Euro 6d-Temp applies since autumn 2017. Does my vehicle meet this emission standard?

The Euro 6d-Temp standard will be valid for new type-approved vehicles from 01.09.2017. This means that all the new models presented to the legislators for type approval must comply with this emission standard.

Type approvals/registrations which have already been completed remain valid under the current law, even if new standards come into force.

7. Why is Porsche not already manufacturing vehicles that meet the already familiar new standards (e.g. Euro 6c) today?

In the context of the model cycles, we ensure that all of our vehicles comply with the standards and regulations required by the legislators over the entire duration of their sale and delivery. Unfortunately, it cannot be ensured that future standards be taken into account over this entire period.

8. I would like confirmation from Porsche that I will not be disadvantaged if my vehicle does not comply with the new standards. / Do I have to have my old Porsche re-tested?

We are unable to provide more extensive confirmation with regard to changes to the legal or regional framework conditions.

9. For what vehicles does the entry restriction in the event of a particulate matter alarm apply in the city of Stuttgart?

The Federal Administrative Court in Leipzig has rejected the revision of the counties of Nordrhein-Westfalen and Baden Wuerttemberg against the court decisions of the administrative courts in Duesseldorf and Stuttgart on 27.02.2018. With this the lawsuit of the German Environmental Agency (Deutsche Umwelthilfe) has been sustained predominantly. Thereby municipalities may impose driving restrictions, without the requirement of existing legal framework from the federal government. We certainly accept the decision of the judges, still, we regret the thereof resulting uncertainty for our customers. According to the decision the counties may decide on driving bans for designated vehicles. Which criteria this will be based on is currently not specified and will probably differ from county to county. For further and concrete statements the necessary arrangements of the counties have to be waited for. Therefore, we cannot give any statement to possibly affected models or cities, as the defining regulations are not yet known.

10. Can I retrofit my vehicle from Euro 5 to Euro 6?

According to the current status, it is not possible to retrofit a Porsche to a more recent standard while maintaining our quality and safety standards.

11. Surely Porsche should be making every effort to ensure that I can continue to use my Euro 5 vehicle without restriction.

Porsche follows the political and media debate surrounding the identification of low-emissions vehicles very closely – including all the potential consequences for today's vehicle fleet. Essentially, we welcome and support considerations that serve for the benefit and protection of citizens. Accordingly, all the current models comply with the Euro 6 standards and therefore meet the latest requirements. Furthermore, Porsche supports the extensive measures of the Volkswagen Group, which were agreed during the "National Diesel Forum“, aimed at further improving the air quality in cities.

12. Can I obtain the blue disc from you? Note: The blue disc does not exist.

Porsche follows the political and media debate surrounding the identification of low-emissions vehicles very closely – including all the potential consequences for today's vehicle fleet. Essentially, we welcome and support considerations that serve for the benefit and protection of citizens. Accordingly, all the current models comply with the Euro 6 standards and therefore meet the latest requirements.

At the same time, please appreciate that it is beyond our power to offer solutions which remain under discussion and which have not yet been clearly defined to date. We hope, that our reference to our close attention to the topic makes it evident that Porsche is concerned with possible optimisations to the emissions performance of our vehicles as well as with the corresponding legislation.

13. When will the particle filter become available for all Porsche models (petrol engines)? Is a retrofit available?

Please appreciate that we are unable to make any specific statements on a possible retrofit of already registered vehicles with regard to model updates at this point in time. You may however rest assured that Porsche is closely monitoring the rapidly changing technology and legislation in this area and will respond accordingly.

14. When will I be able to purchase Porsche vehicles that comply with the Euro 6c standard?

The legislation stipulates that registrations for all new vehicles from 01.09.2018 are only possible with at least Euro 6c.

15. What is a petrol particle filter? (PPF)

A petrol particle filter is a particle filter for petrol engines. This will reduce the emissions of fine soot particulate matter.

16. Why does my vehicle require a PPF?

To date, particle filters are only familiar from diesel engines, however, direct injection technology, which is increasingly being used in petrol engines, increases particulate matter emissions in comparison with intake manifold injection. Because the fuel is injected directly into the combustion chamber, individual droplets can be deposited on the cylinder walls, pistons or valves, where they partly combust only incompletely and remain as minute soot particles.[1]

[1] t-online.de report: VW bringt Partikelfilter für Benzinmotoren (VW introduces particle filters for petrol engines) 3/8/2016, 4:42 p.m. | Hanne Schweitzer, SP-X

17. What effects does the PPF have on the service life of the vehicle, particularly on the engine? / How maintenance-intensive is the PPF?

As is the case with the particle filters already used on diesel vehicles, we do not anticipate any impairment to the service life of petrol vehicles featuring a particle filter.

No maintenance is required or envisaged. There is no effect on the service life of the engine because its thermodynamic and mechanical limits are not exceeded. As a rule, regeneration of the filter is passive, so that the driver is unaware of it taking place. Only in the event of lengthy vehicle operation at very low engine loads in conjunction with short distances and frequent cold starting, are the operating parameters of the engine configured to allow passive regeneration to take place (e.g. higher shifting speeds).

18. Does my vehicle have a particle filter?

Our vehicles with petrol engines do not currently feature particle filters. Our vehicles with diesel engines from EU 4plus are all equipped with a diesel particle filter.

19. Does WLTP affect the vehicle price?

We are currently unable to answer this.

20. Why does Porsche not already indicate fuel consumption according to WLTP today? / Why has Porsche not indicated fuel consumption according to both standards in the past?

We only publish officially approved CO2 and fuel consumption information. Because we do not yet currently have any WLTP-homologated models on the market, we are as yet unable to provide any values. Because the laws on customer communications have not yet been adapted at the start date for WLTP (01.09.2017), the NEDC remains binding.

21. Do I have to have my old Porsche re-tested?

No. The provisions valid at the time of registration apply.

22. What does the change/homologation according to WLTP have to do with the PPF?

Essentially, nothing. The petrol particle filter serves for compliance with the RDE (Real Driving Emissions) limit values.

23. What is the difference between NEDC 1.0 and NEDC 2.0?

NEDC 1.0 values are values, which were determined through the previous NEDC test methods. With NEDC 2.0 vehicles are already typed with WLTP standard; the insofar indicated NEDC values are values which are derived (correlated) from WLTP. In the transition period until 2021, these values will be used for calculating to CO2 fleet.

24. What is the actual fuel consumption of my vehicle (not NEDC or WLTP)?

The actual individual fuel consumption depends on a wide variety of factors (i.e. ambient temperature, traffic situation, driving style, inflation pressure, altitude, inclines, head wind/ tailwind, etc.). The WLTP will however, presumably deliver more realistic CO2 emissions and fuel consumption values.

Information for auditing companies and independent workshops

Additional Information on testing transparency according to the Regulation (EU) 2017/1151 as amended by 2018/1832 Point 5.9 of Part B of Annex II of the European Union can be found within the "Technical Service Information" online application. If you have any questions, please contact piwisadmin@porsche.de.