How to choose realistic EV consumption

Start with measured driving data

The vehicle trip computer over several representative journeys is usually a stronger starting point than one brochure figure. Record distance, displayed consumption, average speed and temperature. Separate urban, mixed and motorway driving instead of averaging journeys that have very different aerodynamic and heating demands.

Separate battery use from grid energy

Dashboard consumption normally represents energy used from the traction battery. A home meter or wallbox records energy drawn from the grid. On-board charging, battery conditioning and other conversion losses mean the grid supplies more than the battery receives. Use the dashboard figure for range and apply a charging-efficiency allowance when estimating the electricity bill.

A real IONIQ 5 observation

WattCalc Lab's editor has observed approximately 28 kWh/100 km in a 2022 Hyundai IONIQ 5 AWD at around 120 km/h in 2–7°C conditions. A summer observation near 27°C was 22.2 kWh/100 km. These are owner observations, not controlled laboratory results: wind, traffic, tyres, precipitation, elevation and cabin settings were not held constant. They illustrate why one consumption input cannot represent every trip.

Build three useful scenarios

Create at least a mild mixed-driving case, a motorway case and a cold-weather case. If your own data is limited, use a plausible range and compare the result rather than selecting a falsely precise percentage penalty. For trip planning, retain an arrival reserve and use live vehicle navigation because weather and road conditions can change during the journey.

Check whether the result is plausible

Multiply distance by consumption and divide by 100. A 250 km journey at 28 kWh/100 km requires about 70 kWh from the battery before reserve and charging losses. If that exceeds usable battery energy, a charging stop is unavoidable even if a brochure range suggests otherwise.

Know what WLTP can and cannot do

WLTP is valuable for comparing vehicles under a common test procedure, but it is not a promise for a particular motorway journey. Hyundai also notes that real range varies with driving style, road conditions and temperature. Use official specifications to confirm battery and charging limits, then use measured consumption for your scenario.

What the owner observations can actually establish

The reported 28 and 22.2 kWh/100 km observations differ by 5.8 kWh/100 km, or about 26.1% relative to the lower rate. For a hypothetical 250 km trip, that is 70 versus 55.5 kWh: a 14.5 kWh planning difference. The arithmetic is useful; a claim that temperature alone caused it would not be supported. The trips were not controlled for wind, traffic, tyres or cabin settings.

For your own comparison, record distance, duration, average speed, temperature, precipitation, start/finish charge and the source of the consumption figure. Group similar journeys before averaging. An average weighted by journey distance is more useful than an equal average of a five-kilometre errand and a long motorway drive.

Sources and scope

Hyundai: original IONIQ 5 announcement. References explain units and technology; hypothetical examples use the site’s own model. Owner observations are not laboratory tests.