2019.0.13.1 COM/EN

Commitment to efficiency

WLTP – A new standard.

The new Worldwide harmonised Light vehicles Test Procedure measures fuel consumption and CO2 emissions.

Background

The legal bit.

The EU established a period during which all legal and technical changes are to be applied. The WLTP 1st Act was created to start introducing these changes.

Now, the next step toward consolidating the WLTP in Europe is the WLTP 2nd Act, which amends the Directive 2007/46/EC of the European Parliament and Commission Regulation (EC) 692/2008 and Commission Regulation (EU) 2017/1151 of the Council.

The WLTP 2nd Act takes effect on 01.01.19 for new types of vehicles and on 01.09.2019 for all vehicles. It includes regulation on new technical concepts and updates for the test, such as Real Driving Emissions (RDE), Evaporation Test (EVAP), In Service Conformity (ISC) and Fuel Consumption Monitoring (FCM), which are all explained in this document, as well as other relevant information about what WLTP involves.

A closer look

Main testing factors.

Aerodynamics

The more aerodynamic a car is, the less air resistance it has and the less fuel it needs. Changes in a car’s aerodynamics can help its long-term efficiency.

Tyre Rolling Resistance

Rolling resistance reduces efficiency through tyre deformation. That’s why it’s important to design tyres to be as efficient as possible.

Mass

Heavy things require more energy to move. A lighter car equals better fuel efficiency and handling.  

Aerodynamics

The more aerodynamic a car is, the less air resistance it has and the less fuel it needs. Changes in a car’s aerodynamics can help its long-term efficiency.

Tyre Rolling Resistance

Rolling resistance reduces efficiency through tyre deformation. That’s why it’s important to design tyres to be as efficient as possible.

Mass

Heavy things require more energy to move. A lighter car equals better fuel efficiency and handling.  

A higher standard

What you need to know.

It’s all about accuracy and relevance. The same test applies to lots of different methods, all around the world. It’s one of the biggest changes ever in the car industry.

Performance

More realistic driving cycles    

Procedure

Stricter car set-up and analysis    

Comprehensive

Accounts for optional equipment    

Precision

More accurate temperatures    

Testing procedures

The WLTP test explained.

Real Driving Emissions (RDE)

Measurement of pollutant emissions (NOx and Particulate Matter (PM)) on the test bench and in real operation when driving on the road.

Evaporation Test (EVAP)

“Tank breathing losses” test in airtight test chambers measures the emissions of the tank and near-engine components in a 48-hour test. 

Fuel Consumption Monitoring (FCM)

Deviation of the values in the WLTP test between the test bench and the vehicle reading (FCM) may not exceed a maximum of 5%.

In Service Conformity (ISC)

Extend WLTP test conditions by testing used vehicles with at least 15,000 km and 6 months (max. 100,000 km and 5 years).

Real Driving Emissions (RDE)

Measurement of pollutant emissions (NOx and Particulate Matter (PM)) on the test bench and in real operation when driving on the road.

Evaporation Test (EVAP)

“Tank breathing losses” test in airtight test chambers measures the emissions of the tank and near-engine components in a 48-hour test. 

Fuel Consumption Monitoring (FCM)

Deviation of the values in the WLTP test between the test bench and the vehicle reading (FCM) may not exceed a maximum of 5%.

In Service Conformity (ISC)

Extend WLTP test conditions by testing used vehicles with at least 15,000 km and 6 months (max. 100,000 km and 5 years).

The new consumption values FAQs

NEDC ("New European Driving Cycle") refers to a test realised on a test bench that has been used throughout Europe since 1992 to measure the exhaust emissions and fuel consumption of passenger cars and light commercial vehicles.

NEDC has been replaced by the globally standardised WLTP ("Worldwide Harmonized Light-Duty Vehicles Test Procedure"). The new method is intended to measure the consumption of a vehicle more realistically and is based on a modified test cycle with stricter test specifications.

In addition to WLTP, emissions in Europe are to be determined in accordance with the RDE ("Real Driving Emissions") test procedure by carrying out the measurements on the road.

While WLTP uses 30 minutes on a chassis dynamometer under standardised conditions, the RDE test takes place on public roads. In the RDE measurement, a route mix with random acceleration and deceleration is used, which takes between 90 and 120 minutes. 

Since September 2017, the transition to WLTP and RDE has been gradual. From September 2018, the WLTP test procedure will be mandatory for all newly registered vehicles, as well as the limitation of the particle number (PN) in RDE. From September 2019, an additional RDE limit value for nitrogen oxides (NOx) will be mandatory for all new registrations.

The values ​​determined by the WLTP test method are intended to reflect consumption and CO2 and exhaust emissions more realistically. This may mean that higher fuel consumption and CO2 emissions are to be reported for vehicles with internal combustion engines. The individual choice of engine and optional equipment will also affect fuel economy and CO2 levels. Depending on national legislation, this may also result in higher CO2 taxes.

From September 2018, all SEAT models will be successively converted to the WLTP test procedure.