It's a convention. Convention is how people commonly refer to something.
After all, you don't buy two quarts of milk, you buy a half-gallon container. Or a quart, or pint or half pint. But I've never heard someone refer to milk in terms of buying a two quart container.
Ditto for oil. Since it's commonly sold to the consumer in terms of quarts, that's the convention when referring to a volume of oil.
Even the gallon containers of oil are frequently referred to as four quart containers. Ditto for the 1.25 gallon containers, they are referred to as 5 quart containers by most folks.
So while pint may be correct, it will not be a commonly used term.
So do you ask for 4oz hamburger patties, or do you get a quarter pounder?
One gets a quarter pounder.
When the oil is half way down, most folks are going to say it's a half quart low since they can't run down to the parts store and buy a pint of oil.
After all, you don't buy two quarts of milk, you buy a half-gallon container. Or a quart, or pint or half pint. But I've never heard someone refer to milk in terms of buying a two quart container.
Ditto for oil. Since it's commonly sold to the consumer in terms of quarts, that's the convention when referring to a volume of oil.
Even the gallon containers of oil are frequently referred to as four quart containers. Ditto for the 1.25 gallon containers, they are referred to as 5 quart containers by most folks.
So while pint may be correct, it will not be a commonly used term.
So do you ask for 4oz hamburger patties, or do you get a quarter pounder?
One gets a quarter pounder.
When the oil is half way down, most folks are going to say it's a half quart low since they can't run down to the parts store and buy a pint of oil.