EU Member States have voted in favour of tighter limits on for cars and vans tested under the latest WLTP and RDE fuel consumption and emissions testing, set to come into force from next year.

The RDE test uses a portable emissions measurement system, similar to the technology used by independent agency Emissions Analytics (pictured)

The Commission’s proposals affect the new Worldwide harmonised Light vehicles Test Procedure (WLTP), designed to offer more representative fuel economy and CO2 emissions data, and the Real Driving Emissions (RDE) tests. Both of which were introduced for new car types last year.

RDE, which is an on-road test to compare in-use NOx emissions with results obtained in the laboratory, is being introduced in stages. The first has a ‘conformity factor’ allowing vehicles to emit 2.1 times more NOx on the road than in the laboratory and is already in place, though not mandatory until September 2019.

From January 2020, RDE2 will bring the conformity factor down to 1.5 times the laboratory results, with the ambition to reach parity by 2023. Cars achieving RDE2 already are exempt from the 4% diesel levy for company cars and VED rises introduced during last year’s Budget.

Under the 4^th RDE Act, which was voted for this week, type approval authorities will be required to check not only the performance of new vehicles, but to carry out ongoing annual monitoring of cars and vans on the road to ensure they still comply. Member States also voted to tighten the forthcoming 1.5x conformity factor down to 1.43x.

The 2^nd WLTP Act proposes tightening the tolerances for adapting the evaporative emission procedure to the new test cycle. From 2021, this will also mandate standardised, easily accessible information about fuel or energy consumption to enable consumers to compare laboratory results with what they are achieving on the road.

Both will come into force from 1 January 2019, if it passes European Parliament and Council scrutiny.

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