Every service station will have a different offering when it comes to the type and grade of fuel sold. Some gas is more expensive than others because of the oil treatment and the kind of refinement that the gas goes through before being available at the pump.
In North America, the most common types of fuel include regular, mid-grade, and premium. You will see these grades referred to by number, which is an octane reading, usually as 87 for regular, 89 for mid-grade, and 92 for premium. Talk about your understanding of fuel grades and how you would explain these grades to a customer at the pump.
