petrol, also known as gasoline, is sold by the imperial gallon in four british overseas territories (anguilla, the british virgin islands, the cayman islands, and montserrat) and six countries (antigua and barbuda, dominica, grenada, saint christopher and nevis, saint lucia, and saint vincent and the grenadines). all of the countries and territories just mentioned also use miles per hour for speed limits and drive on the left side of the road.