2.3.47.2, 2017-10-10 18:26:25
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New standards for consumption values

WLTP : Worldwide Harmonised Light-Duty Vehicles Test Procedure

WLTP

Reflecting real world consumption and emissions values

New consumption values apply as of September 2017 for new to market vehicles. These will be calculated using the new WLTP standard. WLTP stands for Worldwide Harmonized Light-Duty Vehicles Test Procedure. This is a worldwide standardised testing procedure for estimating fuel consumption and exhaust emissions. Find out what this means for you and your Volkswagen Commercial Vehicles.

Anyone wanting to buy a vehicle may want to check the consumption and CO2 emission values. Read and find out how these will be calculated using a new testing procedure in future.

Testing procedure changes

Like NEDC (New European Driving Cycle), WLTP is a laboratory based testing procedure

The WLTP testing procedure has a modified driving cycle and stricter test specifications. These include a longer time span for the measurement along with a higher maximum speed. A summary of the changes can be found below:
 

Conditions:
NEDC
WLTP
Test duration
20 min.
30 min.
Test distance
11 km
23.5 km
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: 34 km/h

Maximum: 120 km/h

Average: 46.6 km/h

Maximum: 131 km/h

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

Timeline

As Volkswagen Commercial Vehicles progresses with the WLTP transition, the following type approval timings will apply:

Passenger vehicles (M type and Category N1 (i)):

  • From September 2017, all new model introductions will be subject to WLTP type approval and Real Driving Emissions (RDE) testing
  • From September 2018, all new sales will have received type approval under WLTP
  • From September 2019, all new registrations will be subject to RDE testing

Light Commercial Vehicles (Categories N1 (ii), N1 (iii) and N2):

  • From September 2018, all new Light Commercial vehicle model introductions will be subject to WLTP type approval and Real Driving Emissions (RDE) testing
  • From September 2019, all new sales of Light Commercial Vehicles will have received type approval under WLTP and all new registrations will be subject to RDE testing

NEDC will continue to be used for the official emissions (CO2) and fuel consumption (MPG) values.  As and when WLTP figures become available for new model introductions, these will also be available for customers. It is worth noting that the NEDC CO2 values will be used for taxation purposes during the 2017/2018 tax-year, and will continue to be until further notice from the HMRC.

NEDC vs WLTP: A comparison

Longer distances, shorter idle times: WLTP puts the testing procedure for a vehicle’s measuring fuel consumption and CO2 emissions to the test. This is how the driving cycles differ.

Goals of the new measurement procedure

The WLTP driving cycle redefines the testing parameters for determining fuel consumption and exhaust emissions.

Improved Transparency

Improved Transparency

In future, a new testing procedure will aim to better assess a vehicle’s actual day-to-day fuel consumption.

WLTP utilises a profile deemed to be more similar to actual day-to-day usage than the previous NEDC standard. This approach is similar to a synthetic laboratory test and primarily serves to enable comparisons between different vehicles without realistically reflecting the actual consumption. Whereas the consumption values were previously measured under abstract laboratory conditions, the new procedure now aims to offer a more precise prognosis of the vehicle’s actual consumption thanks to improved test parameters. WLTP aims to simulate realistic vehicle behaviour in order to achieve far more realistic results.

Comparable testing results

Comparable testing results

One of the primary objectives of the WLTP approach is to provide a standardised means of determining exhaust emissions and energy consumption for different engine systems such as petrol, diesel, CNG and electricity. Vehicles of the same type must deliver the same test results everywhere in the world when the WLTP measurement procedure is followed correctly. This necessary comparability is also why laboratory measurement is essential. 

For this reason, the fuel consumption and emissions are analysed on the roller dynamometer with a dynamic driving profile.

Climate protection

Climate protection

The new consumption information aims to help achieve international climate targets and reduce the burden on the environment.

CO2 reduction is a key aspect of vehicle development. WLTP enables the compliance with international CO2 limits to be checked and documented.

In 2010, the EU alone produced 4.72 billion tons of CO2 emissions. 19% was produced by motor vehicles1. In view of this, the European Union intends to reduce emissions by 20% by 20202. The Euroean Union hopes that this goal will be achieved with the help of WLTP. Just like fuel consumption, the CO2 emissions of a vehicle depend on the specific model. WLTP creates greater transparency when comparing the energy consumption and CO2 emissions of different vehicles. This makes the measurements independent of the manufacturer and vehicle type. They also tend to be higher than the NEDC cycle. As a consequence, individual models and their engines will be further engineered with a view toward climate protection.

Real Driving Emissions (RDE)

Although WLTP will deliver real improvements to the testing regime, it is still a laboratory test and cannot take into account driver style, traffic conditions, weather, gradients or load of the vehicle into its calculation. All of these factors have an impact on the consumption and emissions performance of the vehicle. The RDE test will support in providing customers with this insight.

The RDE test is carried out by fitting Portable Emissions Measuring (PEMS) equipment to the vehicle to record exhaust emissions. The test follows a standardised set of parameters, including:

  • low and high altitudes
  • year-round temperatures
  • additional vehicle payload
  • up-hill and down-hill driving
  • urban roads (low speed)
  • rural roads (medium speed)
  • motorways (high speed)

The results of the RDE test will be used to validate the emissions and consumption values identified as part of the WLTP testing process.

Frequently asked questions

The Worldwide Harmonized Light-Duty Vehicles Test Procedure or WLTP was introduced in September 2017 and represents a new, worldwide standard cycle. WLTP aims to utilise a profile more similar to actual daily driving behaviour than the previous NEDC standard. The new procedure is intended to provide a more realistic representation of a vehicle’s consumption. This is based on a modified test cycle with stricter test specifications.

Both test cycles are carried out in lab conditions. The WLTP test cycle has been redefined in such a way that EU Regulatory bodies view it as more representative of customer driving (ie higher speeds and loads, more dynamic accelerations, fewer and shorter stop phases).  The current NEDC test measures curb weight and rolling resistance. WLTP includes the effect of options on the vehicle’s aerodynamics, rolling resistance and mass when measuring its fuel consumption and emissions.

WLTP will measure a vehicle’s individual CO2 emissions, fuel consumption (MPG) and pollutant emissions (for example NOx). This is the case currently under NEDC, however WLTP will take into account vehicle mass (including optional equipment), tyre rolling resistance class and aerodynamics. The values obtained through WLTP will be comparable worldwide.

WLTP will provide customers with greater clarity in relation to the emissions and consumption values of their vehicle. It is important to note that due to the testing aligning closer to real world emissions, this could result in higher consumption and emissions values for vehicles with combustion engines and a shorter electric range for electric vehicles (including plug-in hybrids).

No. At present no changes to the model portfolio are planned. Individual models and their engines will be developed in order to achieve even higher efficiency and reduce emissions as per the regulations. However, models will not be discontinued as a result of WLTP.

As Volkswagen progresses with the WLTP transition, the following type approval timings will apply:

Passenger vehicles (M type and Category N1 (i)):
•    From September 2017, all new model introductions will be subject to WLTP type approval and Real Driving Emissions (RDE) testing

•    From September 2018, all new sales will have received type approval under WLTP

•    From September 2019, all new registrations will be subject to RDE testing

Light Commercial Vehicles (Categories N1 (ii), N1 (iii) and N2):
•    From September 2018, all new Light Commercial vehicle model introductions will be subject to WLTP type approval and Real Driving Emissions (RDE) testing

•    From September 2019, all new sales of Light Commercial Vehicles will have received type approval under WLTP and all new registrations will be subject to RDE testing

NEDC will continue to be used for the official emissions (CO2) and fuel consumption (MPG) values.  As and when WLTP figures become available for new model introductions, these will also be available for customers. It is worth noting that the NEDC CO2 values will be used for taxation purposes during the 2017/2018 tax-year, and will continue to be until further notice from the HMRC.   

Lab tests enable consumers to compare CO2 emissions and fuel consumption across different manufacturers and models in a controlled environment. As a standardised and repeatable procedure, it allows for comparison across brand and model in similar, standardised conditions.

The current lab test, known as the New European Driving Cycle (NEDC), measures fuel consumption (MPG), CO2 and pollutant emissions against EU regulations, in certain, standardised conditions. The standardised testing procedure allows the comparison of emissions between different vehicle models.

NEDC CO2 values will be used for taxation purposes during the 2017/2018 tax-year, and will continue to be until further notice from the HMRC. We will update customers as further information is shared by HMRC.

Glossary of terms

WLTP is a new lab-based test cycle. It is much more representative of on-road driving, with a wider range of temperatures and speeds. 

When fuels such as petrol and diesel are burned in the engine, carbon dioxide (CO2) is produced and released into the atmosphere. Levels of CO2 emissions are controlled under the ‘Euro’ standards classifications.

A diesel particulate filter is fitted to the exhaust of all Euro 5 and Euro 6 vehicles. It traps particulates before they leave the tailpipe.

EGR is a critical technology used to reduce the levels of NOx emitted by the engine. It involves recirculating exhaust gas back into the engine combustion chamber. This reduces the amount of oxygen, and lowers combustion temperature. Less oxygen and a lower combustion temperature reduces the amount of NOx formed.

Euro 6 is the sixth air quality emissions standard for new vehicles sold in Europe. The European Commission has enforced Euro standards since 1993. Each successive standard has been tougher in its requirements, ensuring that every new generation of vehicle uses the latest, cleanest engine and exhaust technology available.

A lean NOx trap or catalyst is an exhaust after-treatment technology, which reduces the emissions of NOx from the tailpipe (see below). It captures NOx and neutralises it in the exhaust system.

The NEDC is the EU’s official test of new vehicles' air quality and CO2 emissions, and it has been in place since 1996. It is a laboratory test, which operates in strictly controlled conditions and is monitored by a government-appointed approval agency. In the UK, this is the Vehicle Certification Agency (VCA).  

NOx refers to nitrogen oxides or oxides of nitrogen that form when fuels are burned at high temperatures, as in the engine combustion process.  

Particulate matter, commonly known as soot, is a waste material of combustion.    

PEMS, or portable emissions measurement system, is a sophisticated mobile laboratory in a box, which is fitted to the vehicle and analyses tailpipe emissions while the vehicle is driven on the road or a test track. 

Real world refers to conditions that affect a vehicle’s performance when it is being driven on the road, as opposed to being tested in a lab. Real world conditions are infinitely variable, making reliable and repeatable testing of emissions extremely difficult.

RDE stands for Real Driving Emissions and refers to the emissions that a vehicle produces on the road while following a set procedure, rather than in a laboratory environment. On-road emissions can be affected by many different factors, including vehicle and traffic conditions, temperature, weather, road surface and gradient, vehicle load and driving style.

Selective catalytic reduction (SCR) is a highly effective emissions reducing technology used in modern diesel vehicles. This specialist catalytic converter injects a urea based additive, or diesel exhaust fluid that’s often called AdBlue, into the exhaust to convert NOx into harmless nitrogen and water.

Type Approval is the official EU process new vehicles must pass before they can be certified for sale. It applies to many systems - emissions and safety. Vehicles must pass the relevant regulated tests before they are allowed to be put on the market. The VCA is the government-appointed Type Approval authority in the UK.