NEDC versus WLTP

NEDC and WLTP are two successive EU type-approval tests. NEDC applied until the transition that became mandatory in September 2018, WLTP has applied since. The core difference is in the test cycle: WLTP drives longer (over 23 km against about 11 km), faster (up to 131 km/h against 120 km/h), with more dynamics and with options and weight taken into account, while NEDC had many constant and idling phases.

For the same car the WLTP consumption therefore turns out structurally higher than the NEDC figure, roughly 20 to 30 percent for petrol and diesel and more on early plug-in hybrids. That is not a deterioration of the car but a more realistic test. An older model with a low NEDC figure therefore looks more economical than a newer model with a more honest WLTP figure, while the real difference may be smaller or reversed.

So do not compare the two standards one-to-one. For reference models we state which test standard a figure belongs to; do not convert an NEDC value to WLTP with a fixed factor, because the deviation differs per drivetrain.