What is WLTP?

The Worldwide Harmonised Light-Duty Vehicle Test Procedure (WLTP) is a laboratory test designed to measure the fuel consumption, emissions, and range of electric vehicles.

The test uses a standardised cycle and conditions to provide more accurate and comparable results between different vehicles, and is more reliable than the previous test (NEDC). However, it's important to note that the WLTP does not precisely replicate real-world driving conditions.

WLTP Legal Requirement

The WLTP test cycle became mandatory in September 2017 for all new car models sold in the European Union, and for all cars sold there since September 2018. The test is also required in many other regions worldwide, including being the most preferred test method for the New Zealand Transport Agency. According to the legal requirement in New Zealand, the data supplied is representative of a basic specification level vehicle. Any options added to the vehicle will impact fuel consumption and emissions.

During the test, the vehicle is loaded with a specific percentage of the payload (15% for passenger cars; 28% for light commercials), and the air conditioning and other auxiliary systems are turned off. The test cycle lasts about 30 minutes and covers a distance of approximately 23.3 km.

Understanding WLTP range

Benefits of WLTP

• Better simulation of real-world driving conditions, providing a more accurate representation of a vehicle's performance.

• Greater range of driving situations (urban, suburban, main road, motorway)

• Longer test distances: 23.3km.

• More realistic ambient temperatures

• Higher average and maximum speeds: 46.5 kph average; 131 kph maximum.

• More dynamic and representative accelerations and decelerations, capturing the true performance characteristics of the vehicle.

Laboratory test vs on-road performance of cars?

WLTP provides a more realistic representation of on-road conditions compared to the NEDC, it cannot account for all variations. Different drivers have unique driving styles, such as varying acceleration, cornering, and braking habits. Additionally, driving conditions like traffic and weather differ between countries. Therefore, there will still be a difference between emissions measured in lab conditions and those encountered in the real world.

How is an electric car’s range measured?

WLTP Range

Electric cars’ range is a hot topic. Car manufacturers’ official figures are based on a standardised cycle that’s the same for everyone, just like for combustion engines. Let’s take a closer look at the abbreviation WLTP and what it means.


The WLTP test measures the electric range of a vehicle with a standardised test consisting of 4 different phases, with varying levels of acceleration, deceleration, and stops. The test is conducted with a fully charged battery and all electrical equipment turned off. The range is determined by the distance the vehicle can travel on a single charge, from fully charged to fully discharged.

It is important to note that the on-board energy consumption computer in electric vehicles calculates the expected range based on previous driving behaviour and conditions. It provides feedback on energy usage and predicted range, helping drivers optimize range and efficiency by adjusting their driving style. Actual range may vary due to individual driving habits and external factors. The choice of wheels significantly impacts the expected range of an electric vehicle. Different wheel types, such as larger or more aerodynamic designs, can affect efficiency and energy consumption. Wider wheels may reduce range due to increased rolling resistance, while smaller or more aerodynamic wheels maximize range by minimizing drag. When evaluating an electric vehicle's range, it's crucial to consider wheel selection for optimal balance between aesthetics, performance, and desired range.

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

  • From 1st September 2017, all new model introductions were subject to WLTP type approval and Real Driving Emissions (RDE) testing.
  • From 1st September 2018, all new sales received type approval under WLTP.
  • From 1st September 2019, all new registrations were subject to RDE testing. Light Commercial Vehicles (Categories N1 (ii), N1 (iii) and N2):
  • From 1st September 2018, all new Light Commercial vehicle model introductions were subject to WLTP type approval and Real Driving Emissions (RDE) testing
  • From 1st September 2019, all new sales of Light Commercial Vehicles received type approval under WLTP and all new registrations were subject to RDE testing.

WLTP values are now available to our customers. NEDC CO2 values derived from the WLTP test were used for taxation for the tax years 2017/2018; 2018/2019 and 2019/2020. It is only for new passenger vehicles registered after 1st April 2020 (6th April for BiK), that the WLTP values will be used for taxation purposes.

WLTP will introduce much more realistic testing conditions. These include:

  • More realistic driving behaviour;
  • A greater range of driving situations; low, medium, high, extra high and combined;
  • Longer test distances;
  • More realistic ambient temperatures, closer to the European average;
  • Higher average and maximum speeds;
  • Higher average and maximum drive power;
  • More dynamic and representative accelerations and decelerations;
  • Shorter stops;
  • Optional equipment: CO2 values and fuel/energy consumption are provided for individual vehicles as built;
  • Stricter car set-up and measurement conditions;
  • Enables best and worst-case values on consumer information, reflecting the options available for similar car models.

Because of all these improvements, WLTP aims to provide a much more accurate basis for calculating a vehicle’s fuel/energy consumption and emissions. This will ensure that lab measurements better reflect the on-road performance of a car. Only compare fuel/energy consumption and CO2 figures with other vehicles tested to the same technical procedures. These figures may not reflect real life driving results, which will depend upon a number of factors including the accessories fitted (post-registration), variations in weather, driving styles and vehicle load.

The standardised NEDC applied 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/energy consumption.

The Real Driving Emissions (RDE) test measures the pollutants, such as NOx, emitted by passenger vehicles while driven on the road. RDE does not replace the WLTP laboratory test, but complements it. RDE ensures that passenger vehicles deliver low emissions over on-road conditions. Europe is the first region in the world to introduce such on-road testing, marking a major leap in the testing of car emissions.

Under RDE, a vehicle is driven over a wide range of real world driving conditions. Specific equipment installed on the vehicle collects data to verify that legislative caps for pollutants such as NOx are not exceeded.

Conditions include:

  • 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)

To measure pollutant emissions as the vehicle is being driven on the roads, vehicles are fitted with Portable Emission Measuring Systems (PEMS) that provide a complete real-time monitoring of the key pollutants emitted by the vehicle (i.e NOx).

The PEMS used for regulated emissions are complex pieces of equipment that integrate advanced gas analysers, exhaust mass flow meters, weather station, Global Positioning System (GPS) and a connection to the vehicle networks.

There is no ‘standard’ PEMS equipment and equipment manufactured by different suppliers will always deliver slightly different results. The collected data is analysed to check that the RDE trip boundary conditions were achieved and that the emissions were within acceptable levels.

RDE step 1 (with a NOx conformity factor of 2.1) has applied since 1 September 2017 for new car types. It applies to all types as from September 2019.

RDE step 2 (with a NOx conformity factor of 1.0 plus an error margin of 0.5) applied from January 2020 for new types and then from January 2021 for all types.

WLTP replaced the NEDC measuring procedure. New test parameters target more realistic values. See below how the procedures differ:

The WLTP consists of 4 different test phases, each one with a different maximum speed as below. As the speeds of the “Extra high” phase of the WLTP can’t be legally achieved on NZ roads, the government decided to use a WLTP standard including only the first 3 phases. This is known as 3P-WLTP. In order to convert the results into 3P-WLTP, a formula is applied to the 4P-WLTP result.

Low, up to 56.5 km/h

Medium, up to 76.6 km/h

High, up to 97.4 km/h

Extra high, up to 131.3 km/h*

*In New Zealand, the "extra-high" phase of the WLTP test cycle is removed from the fuel consumption and emissions calculations. This is because the extra-high phase involves driving at high speeds that are not within the legal speed limit for New Zealand. The removal of this phase results in more accurate fuel consumption, emissions figures, and range for vehicles in New Zealand.


WLTP more comprehensive than NEDC

WLTP takes additional equipment into account, e.g. bigger wheels, GPS, and spoilers. This influence on CO2 and consumption is measured by the impact the equipment has on rolling resistance, aerodynamics and weight.

Combined Energy Types Disclaimer

The Worldwide Harmonized Light-Duty Vehicle Test Procedure (WLTP) is designed to provide a standardised measurement and enables the consumer to make reliable comparisons between vehicles in terms of energy (fuel and/or electricity) consumption, emissions, and electric vehicle range.

However, it should be noted that the results of this test may not accurately reflect the actual fuel consumption, emissions, or range that a driver might experience in the real world. Actual results may vary depending on various factors such as driving style, road conditions, temperature, weather, vehicle load, and maintenance.

Therefore, the WLTP results should be considered as an indicator of the vehicle's performance and not as a guarantee of the actual energy consumption, emissions, or range that a driver will experience in real-world driving conditions, or for making a vehicle-to-vehicle comparison.

All WLTP test values are provided in accordance with New Zealand Land transport Rule: Vehicle Efficiency and Emissions Data 2022