A recent video of a Cybertruck walk-around accidentally revealed the electric pickup's projected range. The prototype in question still shows the remaining battery and range as a percentage, but its navigation prediction allowed internet sleuths to calculate the estimated range. https://www.notebookcheck.net/Tesla-Cybertruck-range-tipped-at-mediocre-267-miles-by-leaked-interior-images.769167.0.html
This has already been mentioned elsewhere, but that "267 miles" when fully charged could very well be a large rounding error. Depending on how you round the percentages, the range calculation at 100% could even be as high as 320 miles. And this may not even be the range topping trim.
That tesla was towing a trailer. When vehicles tow uses more power. Same implies for gas vehicles. Thus your math is inconclusive.