Is the efficiency the metered amount to charge the car or what the car reports drawn from the battery? If the latter, add ~25% to account for charger and battery charge/discharge efficiency.My PG&E off-peak rate is 42 cents per kWh.
Tesla Model Y LR efficiency is 26.2 kWh/100 miles according to this review.
At the time of this post, 87 octane is $5.79/gal at my local Costco.
So, the cost to power a Model Y is about the same as driving a 2023 Prius or Camry Hybrid. Is it inexpensive compared to other things? Sure. But it is definitely not "stupid cheap" like some EV owners would like you to believe.
Ed