I'm guessing that has more to do with the aerodynamics of the trailer than its weight. Electric vehicles are much more efficient at getting power to the wheels

I'm guessing that has more to do with the aerodynamics of the trailer than its weight. Electric vehicles are much more efficient at getting power to the wheels than gas-powered ones [1], so aerodynamic drag plays a larger factor in range. The Model Y has a super-low drag coefficient of 0.23, and I wouldn't be surprised if the trailer adds considerably more drag than the car itself. [1] https://www.fueleconomy.gov/feg/atv-ev.shtml https://www.fueleconomy.gov/feg/atv-ev.shtml