[Gasoline Fumes]

I use gallons because that's what's displayed on the pump after I fill my tank. And I use miles because that's what's displayed on my odometer. And I use miles per hour because it's what's displayed on every speed limit sign in my country. I use the metric system whenever I can, but it's usually not my choice.

Converting stuff is very easy with Google. Just type "50 mpg in l/100 km" or "75 miles in km" or "15 gallons in liters" into Google and click search.

The information here is very useful regardless of the units used.