Europe is set to adopt tougher emissions standards intended to produce results closer to what cars achieve in real-world driving.
And despite strong efforts by carmakers to delay or dilute the proposed new testing rules, they are expected to take effect in 2017.
Recently OKed by European Commission vice president Frans Timmermans, the "real world" emissions tests will both enforce stricter efficiency standards and change the way cars are tested, according to The Guardian.
The new testing regime is supposed to improve on the current unrealistic New European Drive Cycle (NEDC) protocol, although no details have yet been released.
Emissions tests are generally conducted in a laboratory setting, and it's unclear whether the persistent use of the term "real world" means the new tests would actually be conducted on public roads.
The current NEDC laboratory test is highly optimistic, which why European fuel-economy figures for individual cars are virtually always higher than those produced under the U.S. Environmental Protection Agency (EPA) testing regimen.
Carmakers have also been accused of cheating, and supporters of the stricter test standards say the manufacturers are deliberately attempting to block their implementation.
For their part, carmakers say they'll need more time to comply with new regulations.
BMW i3 electric car undergoing winter testing, February 2013
The planned 2017 date for implementation means many cars already under development or on their way to production will have to be altered, the European Automobile Manufacturers Association (Acea) trade group said.
Acea is sufficiently disturbed by the EU's proposal that it actually drafted its own proposed new testing rules and sent them to Timmermans.
It suggested pushing back the deadline to 2020, as well as numerous changes to test protocols, such as shortening distances driven and raising the minimum allowed temperature.
But with the EU proposal approved and automaker lobbyists seemingly neutralized, the new regulations will pass to EU member states for amendments once they're released.
They are expected to be finalized in September, with full implementation in 2017.