Two cars with the same advertised range can behave very differently on your commute. The label depends on the test cycle, and your results depend on speed, weather and load.
In this article
- Different tests, different numbers
- What cuts range
- How to plan
Different tests, different numbers
WLTP, used in Europe, usually gives a higher figure than the US EPA cycle. The EPA number tends to be closer to what drivers see.
| Factor | Typical effect on range |
|---|---|
| Highway at 75 mph | Down 10 to 20 percent |
| Cold (below freezing) | Down 15 to 30 percent |
| Heavy A/C or heater | Down 5 to 15 percent |
| Roof box | Down 10 to 20 percent |
Figures are typical ranges and vary by car, climate and driving style.
What cuts range
Highway speed, cold weather, roof boxes and heavy cargo all increase energy use. Cold can reduce range by 20 percent or more.
The label is a ruler. The road is the measurement.
How to plan
Take 80 percent of the rated range as a working figure in mixed driving. In winter, assume less.
Worth doing
- Look up EPA and WLTP values for your car
- Check real-world tests
- Use a route planner
- Precondition the battery in cold weather
Practical tip
Keep a 10 percent buffer when you plan a long trip. It covers headwinds, detours and charger problems.
Bottom line
Know the cycle, then adjust for your own driving.
Specifications, prices and rules change. Confirm current details with the manufacturer or the relevant authority before you buy or repair.
