The WLTP is tougher than the old emissions rules.
WLTP rules replace NEDC in September.
It's expected that Mercedes, like any automaker, aspires to be number one. But we've found a case where being at the top of the list is unlikely to be something of which Daimler is going to boast. That's because we're talking about the automaker most likely to cheat the European fuel economy tests.
Testing vehicle emissions in the laboratory is a way to guarantee identical procedures, but it doesn't exactly mimic the results from an on-the-road drive. Ford, for example, famously had a problem with dynamometer testing in the Total Road Load Horsepower (TRLHP) calculations for the C-Max Hybrid. Over in Europe, the authorities are considering new rules that will not affect the emissions levels that need to be reached (those are already in process) but how the vehicles will be tested. Reuters