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 Vehicles Test Procedure (WLTP), to give both car buyers and owners a more realistic understanding of a car's performance.

What is WLTP?

The European Union has developed a new test called the Worldwide Harmonised Light Vehicle Test Procedure (WLTP) which came into effect on 1st September 2017 for new type approvals and 1 September 2018 for all vehicles. This will replace the current New European Driving Cycle (NEDC) test procedure for establishing the official Fuel Consumption and CO2 emissions of new cars.

The new WLTP laboratory test will also be supplemented by an emissions test that measures pollutants directly on the road: RDE (Real Driving Emissions) and was brought in to the new testing regime to provide a closer representation of ‘real-world’ fuel consumption and CO2 figures and provide model specific values at the point of sale.
Image Source: http://wltpfacts.eu

What is RDE?

This takes place on real roads, the RDE test compliments lab tests by measuring that a car delivers low pollutant emissions on the road.

Real driving emission (RDE) tests will measure the pollutants, such as NOx, emitted by cars while driven on the road. RDE will not replace laboratory tests, such as the current NEDC and the future WLTP but it will be additional to them. Europe will be the first region in the world to introduce such on-the-road testing, marking a major leap in the testing of car emissions.

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.

**Test Cycle** Dynamic tests which are more representative of real-driving behaviour

**Cycle Time** Test lasts 30 minutes, an increase of 10 minutes

**Cycle Distance** 23.25 kilometres long, over twice the old distance

**Driving Phases** More dynamic phases: 52% urban and 48% non-urban

**Average & Maximum Speeds** Average speed is 46.5km/h (an increase of 12.5km/h) while top speed is raised to 131km/h

**Optional Equipment** Additional vehicle options (impacting CO2 and consumption) are taken into account

**Gear Shifts** Each vehicle has different, rather than fixed, gear shift points

**Test Temperatures** Measurements now taken at 23ºC (and CO2 values corrected to 14ºC) vs 20-30ºC.

What does WLTP mean for me?

WLTP will facilitate a better means of assessing how high the fuel consumption and CO2 emissions of the vehicle may be on average. At the same time, however, more realistic values will also mean higher consumption and CO2 values for vehicles with combustion engines and a lower electric range for electric vehicles (including plug-in hybrids). These new tests will not have any effect or change the performance of the vehicle.
As Toyota transition to WLTP the following type approval timings will apply:

Commercial and Passenger vehicles (types M1 and 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 registrations will need to comply to WLTP type approval.
From September 2019, all new registrations will be need to comply to RDE testing. Light Commercial Vehicles (Category N1)
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 registrations of Light Commercial Vehicles will need to comply to type approval under WLTP and all new registrations will be subject to RDE testing.