The biggest loss at highway speeds is actually wind. I think wind resistance goes up with the cube of speed.

As a result, electric cars are more efficient in typical city driving. You can see it in the MPG stickers , which are higher in city than highway for EVs

For gas cars, their most efficient speed is typically a steady 35-40 mph. For an electric, it’s 15-20. If there were no wind resistance both these numbers would be substantially higher.