WLTP, the Worldwide Harmonized Light Vehicles Test Procedure, is the standardized laboratory procedure that determines the official range, energy consumption and emissions of passenger cars and light vans. For electric vehicles, it is the reference behind the range figure printed in brochures and configurators across the European Union, the United Kingdom, Japan and several other markets, which makes it a central concept in range & efficiency.
WLTP replaced the older NEDC cycle in Europe from 2017 onward. It was developed under the United Nations framework as UN GTR No. 15 and transposed into European type-approval law. Its purpose is comparability: every car is driven through the same speed profile, under the same conditions, so that two models can be compared fairly, even though no single test can predict the range an individual driver will see.
How the WLTP test cycle works
The WLTP measurement is performed on a chassis dynamometer, a set of rollers that simulates road load while the car stays in a climate-controlled room at about 23 °C. The rollers apply a resistance curve derived from coast-down tests on a real road, so aerodynamic drag, rolling resistance and vehicle mass are represented in the measurement.
The core of the procedure is the WLTC driving cycle, a speed-versus-time profile of about 30 minutes and 23 kilometers for one pass. Most cars, including all common electric vehicles, are tested on the Class 3 version of the cycle, which is split into four phases of rising speed. The table summarizes their approximate characteristics.
| Phase | Duration | Distance | Maximum speed |
|---|---|---|---|
| Low | 589 s | about 3.1 km | 56.5 km/h |
| Medium | 433 s | about 4.8 km | 76.6 km/h |
| High | 455 s | about 7.2 km | 97.4 km/h |
| Extra high | 323 s | about 8.3 km | 131.3 km/h |
The average speed of the full cycle is about 46.5 km/h, and the share of standstill time is roughly 13 percent. This profile represents a mix of urban, suburban, rural and motorway driving, but it remains a compromise: sustained motorway driving at 120-130 km/h makes up only a few minutes of the test.
How WLTP measures electric range
For a battery electric vehicle, WLTP uses the shortened test procedure, known as STP, or a full consecutive-cycle test. In the shortened method, the fully charged car drives dynamic cycle segments followed by constant-speed segments that deplete the battery more quickly, until the vehicle can no longer follow the speed trace. The usable energy taken from the battery and the distance covered yield the all-electric range.
After the test, the car is recharged from the grid and the energy drawn at the wall is measured. Dividing this energy by the range gives the electric energy consumption, expressed in kWh/100 km and including charging losses. This is why the WLTP consumption figure is usually higher than the value shown on the car’s own trip computer, which counts only energy leaving the battery.
Each model receives a range for a low and a high configuration, and the official value of a specific car is interpolated from its mass, rolling resistance of the tires and frontal area. Larger wheels, heavier options and roof rails therefore lower the declared range of the exact car being ordered.
| Value | Unit | What it represents |
|---|---|---|
| All-electric range | km | Distance on a full charge over the combined cycle |
| City range | km | Range over the low and medium phases only |
| Energy consumption | kWh/100 km | Grid energy per distance, including charging losses |
| CO2 emissions | g/km | Zero tailpipe emissions for a battery electric car |
WLTP compared with NEDC and EPA range
WLTP is one of three test systems that readers meet when comparing electric cars, and each one produces a different number for the same car. The older NEDC cycle was short, slow and gentle, so its range figures were notoriously optimistic. The American EPA range uses several cycles and applies a correction factor that brings results closer to real driving.
| Procedure | Main markets | Character | Typical relation to real range |
|---|---|---|---|
| NEDC | Europe before 2017, legacy data | Short, low speeds, little acceleration | Strongly optimistic |
| WLTP | EU, UK, Japan, others | Longer, more dynamic, one combined cycle | Moderately optimistic |
| EPA | United States | Five cycles with an adjustment factor | Closer to mixed real driving |
| CLTC | China | Slow urban-weighted cycle | Often more optimistic than WLTP |
As a rule of thumb, an EPA range figure is often 10-20 percent lower than the WLTP figure for the same model, although the gap varies with the drivetrain and the aerodynamics. Comparisons are meaningful only within the same procedure, never across procedures.
Why real-world range differs from WLTP
The WLTP range is a reproducible laboratory value, not a forecast for any particular trip. Several factors that dominate real energy use are deliberately excluded or held constant during the test, so the everyday range of an electric car can be noticeably below or, in gentle city traffic, even above the official figure.
| Factor | Treatment in WLTP | Effect in real driving |
|---|---|---|
| Ambient temperature | Fixed at about 23 °C | Cold weather can cut range by 20-40 percent |
| Cabin heating and cooling | Climate control off | Heater load reduces range, especially in short trips |
| Motorway speed | Only brief high-speed driving | Sustained 130 km/h raises consumption sharply |
| Payload and accessories | Standard test mass | Passengers, roof boxes and trailers add load |
| Battery aging | New battery | Capacity fade lowers range over years |
Drivers who mainly use motorways should expect the largest shortfall, because aerodynamic drag grows with the square of speed. Efficient equipment such as a heat pump and features such as battery preconditioning narrow the gap in winter, but they are not reflected in the WLTP figure itself.
Using WLTP figures sensibly
The most valuable use of WLTP data is ranking cars against each other. A model with a lower WLTP consumption in kWh/100 km is almost always more efficient in daily use as well, so the consumption value is often a better guide than the headline range, which also depends on battery size.
- Compare the combined consumption of competing models, not only the range.
- Check the WLTP value for the exact wheel and trim configuration, because it can differ by tens of kilometers.
- Plan long trips with a safety margin and a route planner rather than with the WLTP range alone.
- Treat city range as relevant mainly for slow urban use, where electric cars perform well.
Stripped to the essentials
WLTP is a standard driving test done indoors so that every car is measured in the same way. The car runs on rollers, follows a fixed pattern of speeding up and slowing down, and the result is the official range and energy use you see in an advertisement.
Think of it like the nutrition label on food packaging. It lets you compare products fairly, but your real result depends on how you use them. Cold weather, fast motorway driving and running the heater all mean that real range is usually lower than the WLTP number.
Where it is applied
A family comparing two electric crossovers sees WLTP ranges of 450 km and 420 km. Looking closer, they find that the second model has a consumption of 15.8 kWh/100 km against 17.9 kWh/100 km for the first, which carries a larger battery. They choose the second car because it is more efficient and cheaper to run, even with a slightly shorter headline range.
In their first winter, they measure about 330 km per charge on a motorway trip at 120 km/h and around 3 °C, roughly a quarter below the WLTP figure. Because they had used the WLTP value for comparison and planned trips with a margin, the drop matched their expectations and caused no problems.