Worldwide harmonised Light-duty vehicles Test Procedure (WLTP) and Real Driving Emissions (RDE)

KEY POINTS

Requirements for EU type approval

• To receive an EU type approval¹ with regard to emissions, the manufacturer must show that the vehicle complies with the requirements set out in this regulation when tested under the specified procedures.
• All vehicles must respect the tailpipe (exhaust pipe) emission limits set out in Regulation (EC) No 715/2007 when tested in RDE and WLTP tests, along with a series of other tests that include checking for evaporative emissions (i.e. emissions originating from the fuel tank system) or checking at low ambient temperatures.
• OBD systems must be installed on all vehicles to identify all forms of deterioration or malfunction over the lifetime of the vehicle – the regulation sets out requirements for the OBD system during normal use.
• Manufacturers must install devices to continuously measure the quantity of fuel/energy used to operate the vehicle (on-board fuel and/or energy consumption monitoring device, OBFCM device).

Applying for EU type approval

• Manufacturers must submit an application to the approval authority for EU type approval of a vehicle with regard to emissions, which includes:
  • the results of the regulated emission tests;
  • detailed written information fully describing the functional operation characteristics of the OBD system;
  • a description of the provisions put in place to prevent tampering with and modification of the emission-control computer and the odometer, including the recording of mileage values;
  • an extended documentation package that allows an authority to assess whether the ban on ‘defeat devices’² that reduce the level of emission control is respected.
• If the relevant requirements are met, the approval authority grants a Euro 6 emissions type approval and issues a type-approval certificate.

Conformity of production

Checks must be made by the manufacturer to ensure that all vehicles produced by the manufacturer conform to the type approval and respect the emission limits.

In-service conformity

Checks must be performed to ensure that properly maintained and used vehicles respect the emission limits during their useful life, which is set between:

• 15,000 km or 6 months, whichever occurs later; and
• 100,000 km or 5 years, whichever occurs sooner.

Pollution control devices

• Pollution control devices such as catalytic converters and particulate filters must be type-approved as separate technical units.
• The relevant requirements shall be deemed to be met if the replacement pollution control devices have been approved in accordance with UNECE Regulation No 103.

Emissions of plug-in hybrid vehicles

Since recent studies have shown a considerable difference between the average real-world carbon dioxide (CO₂) emissions of plug-in hybrid electric vehicles and their CO₂ emissions determined by the WLTP, to ensure that the CO₂ emissions determined for such vehicles are representative of real driver behaviour, the utility factors applied for the purpose of the CO₂ emission determination at type approval are revised in amending Regulation (EU) 2023/443.

The regulation specifies new utility factors³ on the basis of available data applicable from September 2023. Those factors will be revised to better reflect real-world conditions, taking into account data from fuel consumption monitoring devices on board such vehicles and collected in accordance with Commission Implementing Regulation (EU) 2021/392 in 2025 and again in 2027.