A Toyota Corolla with a 1.8L engine requires 6.2 liters of gas to drive for 100 kilometers on a highway. But on city roads, it would require 7.9 liters of gas. A 2022 Ford F-150 requires 9.4 and 12.1 liters per 100 km for highway and city driving, respectively.
This is a great little summary. I knew these principles but this puts 2 and 2 together nicely.