Many US gas stations switched to liters for a while during the original "gas crisis" in the 70s. One crooked station near my house switched to liters without saying so - they simply covered or removed "gal" on the price signs, so they said like $0.85 with no units, so the price for a gallon was over $4. To further hide it, when customers asked to fill the tank the attendants only put in about a quarter tank, so the price would be realistic for a fillup measured in gallons. It pissed off one guy so much he stood in front of the place for about a month with a ginormous sign that said "BUYER BEWARE! REG OVER $4/GAL".