WLTP – All about the test procedure - digitalsecurity.web.id

Since 1 September 2018, the WLTP (Worldwide harmonized light-duty vehicles test procedure) has been in force for all new cars imported into Switzerland. Here we explain why a new test procedure was introduced, what effects it has and what has changed at AutoScout24.

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What does WLTP stand for?

WLTP stands for "worldwide harmonized light-duty vehicles test procedure" and is a standardised vehicle approval procedure. During the test procedure, different driving cycles are simulated to determine the fuel consumption, CO₂ emissions and other pollutant emissions of a vehicle.

Why do we need a test procedure for vehicle emissions?

The WLTP procedure was introduced to measure more accurately how many pollutants a vehicle produces and how much fuel it consumes. This is to check whether the legal regulations are being complied with. All vehicle models that are registered and registered in the EU must be tested for their pollutant emissions and consumption as part of the approval process. In order to be able to dispense with the purchase of expensive test laboratories, Switzerland is adopting the EU regulations unchanged. On the basis of this data, the car manufacturers also indicate the consumption values.

Why was the WLTP procedure introduced?

The NEDC procedure (New European Driving Cycle), which is valid until 2018/2019, came into force in 1970 and was the standard until 1992. The regulations in the NEDC offered car manufacturers some legal loopholes to optimize pollutant emissions and consumption values as much as possible. The problem? The emission values were only achieved under laboratory conditions. In addition, the predefined standard test route in the NEDC did not necessarily represent the driving profile of the average driver.

As a result, fuel consumption and emissions in real driving practice deviated greatly from the stated values. The higher than expected gasoline, diesel or electricity consumption often led to frustration and anger among car buyers.

The most important details about the introduction of the WLTP procedure and its impact are briefly explained to you in the following video.

NEDC vs. WLTP: What exactly has changed?

The WLTP procedure (worldwide harmonized light-duty vehicles test procedure), which came into force in 2018, is intended to provide more practical consumption and emission values and create a globally comparable standard. In addition, the driving profile should better reflect a real driving situation. New test cycles have been defined for this purpose.

The most important changes in the test are:

NEDC (old procedure)	WLTP (new procedure)

Duration of the test	20 minutes	30 minutes
Route	11 km	23.25 km
Proportion of service life in the test	25 percent	13 percent
Average speed	34 km/h	46.6 km/h
Maximum speed	120 km/h	131 km/h
Impact of optional equipment & air conditioning	Will not be considered	No air conditioning. Optional extras that affect weight, power consumption and aerodynamics are taken into account.

Due to the adapted, stricter and more realistic test procedure, higher consumption values are determined with the WLTP procedure than before.

Emissions under real driving conditions – RDE

The higher exhaust emissions in reality are a nuisance for many. The WLTP cycle is also not perfect and cannot take into account individual factors such as personal driving style, load, geographical conditions (gradients). This is why the RDE procedure, short for "real driving emissions", was introduced. RDE is used exclusively to measure nitrogen oxide and carbon monoxide emissions and particulate emissions. Fuel consumption is not determined.

The measurements are not carried out in the laboratory, but on public roads. For this purpose, a portable measuring device, called PEMS, is attached to the car. Since the car drives over different road surfaces and is tested under different conditions, more realistic values can be collected. But even this test procedure is not perfect. This is because the portable measuring device is less accurate than the devices that can be used in the laboratory. RDE thus serves as a supplement to the WLTP procedure.

WLTP: The influence on hybrid and electric cars

In the case of hybrid cars, the connection to WLTP is a little clearer, but you are probably wondering what a test procedure for exhaust emissions has to do with electric cars. Although electric cars do not actively emit pollutants, the WLTP procedure is also relevant for electric vehicles. This measures not only pollutant emissions, but also consumption. When buying electric cars, the potential range is a decisive selling point. However, since this varies greatly depending on the circumstances and driving style, it is difficult to compare different figures. The ranges according to WLTP therefore provide a uniform measurement value that serves as a basis for comparison.

Regulation 101 also applies to hybrid cars. They thus represent a special case. If a hybrid vehicle can drive 25 km purely electrically, the consumption of the combustion engine may be halved. This regulation makes it difficult to compare different hybrid vehicles and promotes a lack of transparency. So if you want to buy a hybrid car, you should keep this regulation in mind so that you can classify the information correctly.

How can you tell if a car has been tested according to the WLTP procedure?

All cars are classified into the so-called "Euro" emission standards. Since 1 September 2014, the Euro 6 emission standard has been in force for newly registered vehicles.

This emission standard restricts the emission of pollutants. According to the law, the following limit values apply:

CO₂ emissions (mg/km)	NOx emissions (mg/kg)	Particle mass (mg/km)

Diesel Passenger Cars	500	80	4,5
Petrol engine	1'000	60	4,5

The various emission standards (6a, 6c, etc.) indicate how the emissions were measured. Cars that have been tested with the NEDC procedure, for example, receive a Euro 6b classification, but do not meet the Euro 6c emission standard.

Cars tested according to WLTP meet the Euro 6c, Euro 6d and Euro 6d-temp emission standards. If you are looking for a vehicle with WLTP values, you should therefore inquire about these emission standards.

What does this mean for me?

Since September 2018, we have been enabling the subdivision of the Euro 6 emission standard (Euro 6a, Euro 6b, Euro 6c, Euro 6d, Euro 6d-Temp) in our advertisements. So you have the option of choosing which emission standards should be met in your future car.

What do I need to consider when buying a used car?

On the energy label, in advertising and in sales documents, the consumption values had to be stated in NEDC values by 31.12.2019. For vehicles that have already been measured according to WLTP, the NEDC values have been calculated back to 31.12.2019 (or physically measured).

When comparing advertisements, it can therefore happen that two identical vehicles (which differ only on paper by a different type certificate number) have different consumption values, even if the mileage has not changed.