Will WLTP end the discrepancy between the laboratory and on-road performance of cars?

Even though the Worldwide Harmonised Light Vehicle Test Procedure (WLTP) will provide a far more realistic representation of conditions encountered on the road than the old NEDC lab test (New European Driving Cycle), it will not cover all possible variations. Moreover, each individual driver will continue to have a different driving style: one driver might accelerate faster, take corners faster or brake more suddenly than another who might drive more conservatively.

Given that driving behaviour, traffic and weather conditions will continue to differ from one country to another, there will still be a difference between emissions measured in lab conditions and the real world. However, as there is no single real-world emission value, only values obtained by standardised laboratory tests allow us to directly compare the emissions and fuel consumption of different car models from different car manufacturers.

What is WLTP and how does it work?

What is the purpose of the WLTP lab test?

What are the benefits of WLTP?

From NEDC to WLTP: What will change?

When will the WLTP changes take place?

How to ensure a smooth transition to WLTP?

Transition Timeline: From NEDC to WLTP

From September 2017

Cars type approved using NEDC before September 2017 can still be sold.
WLTP type approval testing will be introduced for new car types.
Some cars will have ‘old’ NEDC values, while others will already be certified under the new WLTP conditions.
The industry would like to start using WLTP-based results for general consumer information (eg sales brochures and websites).
During the period of transition (up until the end of 2018), only NEDC values should be used on labels and information in dealerships to enable consumers to compare different cars.
It is expected that national tax regulations will continue to be based on NEDC values.

The same car suddenly has two different CO2 values, why is this?

The NEDC value of a car suddenly increased, what happened?

From September 2018

All new cars must be certified according to the WLTP test procedure, and no longer on NEDC.
An exception should be made for end-of-series vehicles to allow for a limited number of unsold vehicles in stock that were approved under the old NEDC test to be sold for one more year.

Will my fuel consumption increase under WLTP?

From 1 January 2019

All cars in dealerships should have WLTP-CO2 values only to avoid any confusion among consumers, in the view of the automobile industry.
National governments should adjust vehicle taxation and fiscal incentives to WLTP values, respecting the principle that WLTP should not have a negative impact on consumers.

Will WLTP affect how much car tax I pay?