60mpg (us) is 72mpg (uk), or 4l/100km. A Vauxhall Corsa may claim that[0], but I've got one at the moment as a rental and don't get anywhere near that, more like 45-50mpg (uk) - so about 40mpg (us).

[0] https://www.parkers.co.uk/best-cars/most-economical-cars/