I take a fully charged 2019 BMW i3s and take it out on the New Jersey Turnpike for a 70-mph (113 km/hr) highway range test.

Test notes:

Tires were set before the drive to BMW's recommended pressure.
Temperature: 87 F (30 C) degrees at the start and 95 degrees F (35 C) at the end. I had the air conditioning on and set to 70 degrees the entire drive.
Wind: Mild, 4-5 mph crosswind.
Comfort driving mode was used.


Results:
141 miles (227 km). The EPA range rating is 153 miles.
Efficiency: 3.6 mi/kWh - 17.2 kWh/100 km