Unit Confusion: Wh/mi vs Wh/km
Depending on where you live or what car you drive, the efficiency number on your dashboard might look very different.
🇪🇺 Europe / World (Wh/km)
Watt-hours per kilometer
Standard for Tesla in Europe, Australia, and Asia.
Lower is better.
• Excellent: < 140 Wh/km
• Average: 160-180 Wh/km
🇺🇸 USA (Wh/mi)
Watt-hours per mile
Standard for Tesla in North America.
Lower is better.
Since a mile is longer than a km (1.6x), the numbers are higher.
• Excellent: < 230 Wh/mi
• Average: 250-300 Wh/mi
What is MPGe?
MPGe (Miles Per Gallon equivalent) is a US standard created to help gas car drivers understand EV efficiency. It converts electricity usage into "gallons of gas energy."
33.7 kWh of electricity contains roughly the same energy as 1 gallon of gasoline. If your EV can travel 100 miles on 33.7 kWh, it gets 100 MPGe.
Winter Range Loss
Whether you are in the US or Europe, cold weather impacts EVs significantly. Expect a 20-30% range drop when temperatures fall below freezing (0°C / 32°F) due to cabin heating and reduced battery chemistry performance.