Since the 1980s, European new car emissions and fuel economy tests have been carried out using the New European Driving Cycle (NEDC). From 1 September 2017, a new test has been introduced, the Worldwide Harmonized Light Vehicle Test Procedure (WLTP), to give both car buyers and owners a more realistic understanding of a car's performance.

NEDC to WLTP: what’s changing?

With advances in vehicle technology and changes in driving conditions, the near-40-year-old NEDC driving cycle test is being replaced. To give you a more accurate way of calculating and comparing a car’s fuel consumption and emissions, the new WLTP test introduces more realistic testing conditions, so that lab measurements better reflect the on-road performance of a car.

Introducing greater clarity

Between September 2017 and September 2018, all new cars will have to conform to the WLTP test procedure (light commercial vehicles follow one year later). For Toyota, the first model to be certified under WLTP will be the Prius, in Q4 2017.

At Toyota, we welcome the change to WLTP, which will provide our customers with a more accurate basis for calculating fuel economy and emissions. As a leader in clean mobility, we have spent decades researching how to make vehicles that are kinder to the environment, producing technologies such as hybrid that have proved their value in reducing greenhouse gas emissions, and helping the move towards a low carbon society.

“Hybrid is the backbone of our powertrain programme and will help us cut our vehicle carbon emissions by 90% by 2050 compared to 2010.”

Dr. Johan van Zyl, President and CEO of Toyota Motor Europe

Everyday tests, realistic results

The new WLTP tests will ensure that lab measurements now better reflect the situations you will experience in everyday life. This means that fuel consumption and emissions values displayed for new cars are a far better representation of what you are actually likely to achieve.

Discover Toyota’s quest for cleaner mobility

Still have questions?

Q. Will my car’s real-world fuel consumption change?

A. No, your actual fuel consumption will remain the same, but it’s likely that your vehicle will get a higher official CO2 value and fuel consumption values due to the more rigorous WLTP test cycle – closer to what you observe.

Q. Will WLTP fuel consumption and CO2 values reflect what I can expect?

A. Like NEDC, WLTP continues to be a laboratory test. As driving styles and conditions vary, some variance between official values and what a consumer achieves is possible.

Q. Why has the NEDC value of my car suddenly increased?

A. For a transitional period of time (until the end of 2020), NEDC values will still be generated in parallel to WLTP values. As the old NEDC procedure can no longer be used, regulations mandate that WLTP CO2 values will be translated back to NEDC-equivalent values by means of a ‘correlation exercise’.

This will be carried out using either a simulation tool developed by the European Commission or through physical re-testing, which may result in higher NEDC CO2 values for your car as this will be an updated version of NEDC (based on WLTP).

Q. Will WLTP test for other air quality pollutants?

A. Yes, WLTP is also used to measure substances such as carbon monoxide (CO), hydrocarbons (HC) and oxides of nitrogen (NOx) and particles (PM/PN).

Q. When will light commercial vehicle values change?

A. WLTP certification will be mandatory for all light commercial vehicles (Categories N1 (ii), N1 (iii) and N2) from 1 September 2019, one year after passenger cars.