New standards for consumption values
WLTP revises consumption values.
New consumption values will apply as of September 2017. 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.
A new testing process - thanks to WLTP.
WLTP reforms vehicle manufacturers’ measuring and testing processes. An overview of the new procedure.
What is WLTP?
Anyone wanting to buy a car 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.
How much fuel does a vehicle consume? Like other manufacturers, Volkswagen now aims to answer this question more precisely with the new and standardised WLTP driving cycle. The new test cycle for measuring fuel consumption is perceived to be more closely oriented on everyday driving behaviour. As of September 2017, it will replace the current NEDC standard.
WLTP stands for Worldwide Harmonized Light-Duty Vehicles Test Procedure. This worldwide harmonised testing procedure for light-duty vehicles describes a new testing method to estimate a vehicle’s fuel consumption. This procedure is based on real recorded driving data. In future it will help to simulate realistic driving even under laboratory conditions. That is why WLTP not only takes into consideration various situations and speeds but also a vehicle’s different equipment variants and weight classes.
Good reasons for WLTP.
Using real driving data collected worldwide, WLTP aims to deliver more realistic consumption values. Read and find out what will change with the introduction of the new testing procedure.
The consumption of a vehicle will differ from the manufacturers specifications. That is why the reliability of the results measured using the New European Driving Cycle (NEDC) has often been criticised. This is due to the fact that real consumption is highly dependent on individual driving behaviour and the vehicle’s equipment. One example is whether a vehicle is primarily used in the inner city, on rural roads or the highway. To address these differences, the theoretical framework of the NEDC has been revised to reflect a more dynamic driving profile. Drawing on statistical surveys and the analysis of average user profiles, this profile features higher acceleration, a higher average speed and a higher maximum speed. Instead of combining simulated urban and extra-urban driving, the vehicle is now tested in four different speed ranges.
The exhaust and consumption values measured as per WLTP must be specified for all new models launched as of 1st September 2017. This applies in Europe and many other countries worldwide.
NEDC and WLTP.
WLTP will replace the NEDC measuring procedure in autumn 2017. New test parameters target more realistic values. Read and find out exactly how the procedures differ.
The new 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. The new changes at a glance:
Four speed ranges are measured on the roller dynamometer after a cold start: up to 60, up to 80, up to 100 and above 130 km/h. The vehicle brakes and accelerates repeatedly within these phases. The maximum speed is, thus, 10 km an hour higher than the NEDC. In addition, the average speed of approximately 47 km/h is also significantly higher (previously approx. 33 km/h). A temperature of 23°C is specified for the testing chamber. Previously, the NEDC required 20-30° C. The entire WLTP driving cycle lasts approximately 30 minutes. In contrast, the NEDC only requires 20 minutes. The distance has been more than doubled to 23 instead of 11 kilometres. Unlike the NEDC, WLTP takes into account specific optional extras and how they influence the weight, aerodynamics and energy consumption (standby current). Optional extras that consume energy such as the air-conditioning or seat heating remain switched off during the testing process.
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.
An overview of NEDC.
The standardised NEDC applies for all passenger vehicles and light commercial vehicles. It was introduced by the European Union in 1992 in order to provide comparable values for fuel consumption. The following overview shows you the framework on which these measurements are based.
- The temperature in the testing chamber is 20-30°C.
- The distance is 11 km.
- The cycle takes 20 minutes.
- The cycle consists of two phases: 13 minutes of simulated urban and 7 minutes of simulated extra-urban driving.
- The average speed is approximately 33 km/h.
- The idle proportion is 25%.
- The maximum speed is 120 km/h.
- The shift points for models with a manual transmission are precisely defined.
- Optional extras and air conditioning are not considered.
An overview of WLTP.
The Worldwide Harmonized Light-Duty Vehicles Test Procedure or WLTP is a worldwide standard for testing passenger vehicles and light commercial vehicles. As of 1st September 2017, it will aim to provide more realistic consumption specifications with its considerably more dynamic testing parameters. See the description in the following.
- The temperature in the testing chamber is 23°C.
- The distance is 23 km.
- The cycle takes 30 minutes.
- It consists of four phases (low, medium, high, extra-high).
- The average speed is approximately 47 km/h.
- The idle proportion is 13%.
- The maximum speed is above 130 km/h.
- The switching points are calculated individually in advance for each vehicle.
- The vehicle weight and additional equipment are factored into the analysis.
- All possible engine and transmission combinations are measured.
Goals of the new measurement procedure.
The WLTP driving cycle redefines the testing parameters for determining fuel consumption and exhaust emissions. The changes at a glance:
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.
The new WLTP standard ensures comparable test results worldwide.
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.
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 vehicles*. In view of this, the European Union intends to reduce emissions by 20% by 2020**. 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.
*) The information is based on the paper “Mobility of the Future – Safe and Tested”, 16.03.2015, TÜV e.V.
**) The information is based on the paper “CO2 regulation for passenger vehicles” published by the German Economic Institute of Cologne in 2013.
A driving cycle defines the requirements and conditions for measuring a vehicle’s fuel consumption and CO2 emissions. The goal is to simulate a realistic, average journey with the vehicle. The driving cycle specifies certain conditions such as the starting temperature, speed and measurement duration to ensure that the manufacturers can provide comparable values when registering and selling a vehicle.
The New European Driving Cycle (NEDC) was introduced by the European Union on 01.07.1992. It was intended to guarantee a standardised means for better comparability between vehicle-specific consumption. However, it does not claim to reflect the actual day-to-day consumption.
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.
The NEDC testing cycle introduced by the European Union in 1992 is outdated and cannot accurately represent individual, day-to-day driving behaviour. In contrast, the new WLTP standard aims to ensure that the consumption values measured during a model’s type approval testing are more realistic.That is why both the procedure and the driving cycle differ from the NEDC standard.
For example, the redefined test parameters include a longer testing distance, longer driving times, shorter idle times and higher average speeds. They also take into consideration optional extras. These new parameters generally result in higher consumption specifications.
The new WLTP cycle became mandatory on 01.09.2017. As of September 2017, all new passenger cars and engines introduced by vehicle manufacturers must be specified using WLTP fuel consumption and CO2 emission figures. As of 01.09.2018, all new passenger cars will require consumption and exhaust specifications as per WLTP.
No. At present no changes to the model portfolio are planned. Individual models and their engines will have to be further engineered 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.
Yes, there are. The driving cycles for exhaust and consumption measurement developed in Japan (JC 08) and the USA (FTP 75) are more closely oriented on specific situations on the country’s roads. For example, Japan’s driving cycle includes numerous stop-and-go phases and is carried out twice, once as a cold start and once as a warm start.
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.
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 car 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 car to record exhaust emissions. The test follows a standardised set of parameters, including:
• low and high altitudes
• year-round temperatures
• additional vehicle payload
• up- 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.