Real range vs WLTP: how far an electric car really goes

Updated 7 October 2026 · With measured consumption and the evrouteplan simulator model

The WLTP range on the data sheet comes from a lab test with a lot of city driving, an average speed of 46.5 km/h and no heating or air conditioning. On the motorway at 120 km/h, an electric car does roughly three quarters of that figure: the BYD Sealion 7 Excellence, with measured consumption, 74%. In the cold, less. Here is where the gap comes from and how to work out yours.

1. What WLTP measures (and what it does not)

WLTP is the European type-approval test. It does very well what it was designed for: comparing cars with each other under the same conditions. But those conditions look nothing like a motorway trip:

• The cycle lasts about 30 minutes and covers about 23 km, with urban and rural sections and a short fast part. The average speed is 46.5 km/h and the top speed about 131 km/h, held for only a few seconds.
• It is done in a lab, at about 23 °C, with no wind, no hills and the climate control off.
• The WLTP range is what the whole battery gives, from 100% to 0%.

A long trip is the opposite: high, sustained speed, sometimes cold or heat, wind, hills, and nobody runs the battery down to 0%.

2. What the measurements say

For now we have constant-speed consumption measurements for only one model in the catalogue: the BYD Sealion 7 Excellence (91.3 kWh usable, 502 km WLTP, 18.2 kWh/100 km rated consumption), with the figures published by evkx.net. They are constant-speed figures, on the flat and without climate control:

At 90 km/h it does about 435 km, 87% of WLTP. At 120 km/h, about 373 km: 74%. Between the two speeds consumption goes from 21.0 to 24.5 kWh/100 km, because air resistance grows with the square of speed.

3. A quick rule for any car

For cars we do not have measurements for yet, the simulator uses a general table that multiplies the WLTP consumption according to speed. Expressed as range, it looks like this (flat, 20 °C, no wind):

It is an assumption, not a measurement, and we say so. At 120 km/h it matches what was measured on the Sealion 7 (74% against 74%); at 90 km/h the table is more cautious than the measurement (80% against 87%). Below 60 km/h the simulator assumes you use what WLTP says (100%): in town and in mild weather that is the reference figure, and some cars beat it.

4. Cold: heating and denser air

In the cold you use more for two reasons. The first is heating: the simulator counts 0.11 kW for every degree below 18 °C, so at 0 °C that is about 2.0 kW all the time. The second is that cold air is denser and slows the car more. This is the effect on the Sealion 7 at 120 km/h, according to the simulator model:

Compared with 20 °C, it loses 8% of its range at 0 °C and 10% at −5 °C. The heating in the model is the same for every car, because we do not yet have climate-control consumption measured model by model: a car with a heat pump may use less, and one without, more.

5. In town, cold weighs more than on the motorway

Heating uses the same per hour whether you go fast or slowly, but in town you cover far fewer kilometres in that hour. At 0 °C, the 2.0 kW of heating mean about 4.0 kWh/100 km at 50 km/h (22% more than the Sealion 7’s WLTP consumption) and only 1.7 kWh/100 km at 120 km/h (7% more than its consumption at that speed). That is why short winter trips are the ones that surprise people most.

6. The range you really use on a trip

On a trip you do not go from 100% to 0%: the usual thing is to reach the charger at 10% and leave at 80%, which is where fast charging is fast. That is 70% of the battery. With the Sealion 7 at 120 km/h, according to the simulator model:

• At 20 °C: about 258 km between charges (70% of 369 km).
• At 0 °C: about 237 km (70% of 338 km).

That is the number to plan with, not the 502 km on the data sheet.

7. How to work out yours

• Take the WLTP range of your version and multiply it by the percentage for your speed from the table in point 3 (at 120 km/h, 74%).
• If it is cold, take off what point 4 shows (at 0 °C, about 8% more).
• To know how far you go between charges, keep 70% of the result.

Or let the route planner do it: it uses measured consumption where it exists, the wind and temperature forecast for your departure date, the hills on the route and your car’s charging curve, and tells you where to stop.

How these figures were calculated: the measured consumption is what evkx.net publishes for the BYD Sealion 7 Excellence at constant speed, without climate control; range is usable battery divided by consumption. The general speed table, the heating (0.11 kW per degree below 18 °C) and the air-density correction are those of the evrouteplan simulator in October 2026. The WLTP cycle data are those of the European type-approval test. See data sources.