EC Closes CO2 Loophole in New WLTP Emission Test

The European Commission has tightened emission testing protocols after determining that carmakers were gaming the process to make it easier to meet future carbon dioxide goals.

The change may force some companies to re-test some of their models, according to environmental lobbying group Transport & Environment.

The EC’s move follows a Financial Times report last summer that said carmakers were deliberately raising CO₂ emissions on vehicles ahead of the bloc’s move to the new WLTP (world harmonized light vehicle test procedure) last September. Doing so set a higher baseline, which resulted in an easier target under WLTP.

The result—depending upon whether or not a given carmaker manipulated the test—were baseline CO₂ levels that rose between 1% and 81% compared with the previous test protocol, according to T&E. The group did not identify which companies gamed the tests.

The EC determined that some carmakers raised their baseline CO₂ levels by turning off such fuel-saving systems as automatic stop-start, using more aggressive shift patterns and switching the engine management system from Eco to Sport.

The updated WLTP now requires companies to use operating settings throughout the tests that result in the lowest emission levels. One objective in switching to the new protocol was to narrow the big gap between calculated and real-world fuel economy caused by carmakers gaming the previous certification process.