On each new car, the manufacturer displays the number of miles the car will travel on 1 gallon of gas. For example, the vehicle may get 35 miles per gallon (mpg) on the highway and 24 mpg in the city. If traveling in another country, they may use kilometers instead of miles and liters instead of gallons. Here's how to convert mpg to the metric system.
Convert the miles into kilometers; 1 mile equals 1.609344 km. For rounding purposes, 1 mile equals 1.61 km.
Multiply the miles by kilometers. If your mpg is 35, multiply 35 by 1.61. In this instance, 35 miles is equivalent to 56.35 km, so the car goes 56 km on a gallon of gas.
Convert gallons to liters. One gallon equals 3.78541178 liters. Again, for rounding purposes, 1 gallon equals 3.79 liters.
Multiply the gallons by liters. Using the example from Step 2, multiply 1 by 3.79, which is 3.79 liters. So the car goes 56 km on 3.79 liters of gas.
