Here's what to do if you pay for an oil change you didn't actually receive.

Dear Car Talk | May 01, 1995
Dear Tom and Ray:
Grandma
TOM: It may be even worse than you suspect, Grandma. If the oil really looks dirty (i.e. black), they probably didn't drain ANY of your old oil out. They may have just changed the filter, added a quart, and sent you over the river and through the woods.
RAY: And wouldn't that frost your girdle?
TOM: When you remove the drain plug, the vast majority of the oil pours out very quickly. Within a minute, it's down to a trickle. And at that point, you've got--at most--half a pint still in the engine. And that's not enough to make the other four "new quarts" look dirty.
RAY: Besides, it would be difficult to stop the majority of oil from gushing out during that first minute. It would be a horrible mess... like trying to cap the milk bottle while you're holding it upside down and pouring it. The boiling hot oil would run right down their arms. And even these neanderthals wouldn't subject themselves to that sort of unpleasantness just to save two bucks.
TOM: So if the oil really looks dirty, there are only two possibilities. One is that they didn't even get close to letting all the oil drain out (which, as we said, is difficult even for a lazy person to do). Or, they changed your filter, dumped in one new quart, and charged you for the whole oil and filter change.
RAY: So if I were you, I'd take two actions. One, I'd never go back to that place because they're either very lazy or crooked. And two, I'd call the Attorney General's office and tell them that if they're ever thinking about doing an automotive repair "sting" operation, you have a very promising candidate for them.
Grandma
TOM: It may be even worse than you suspect, Grandma. If the oil really looks dirty (i.e. black), they probably didn't drain ANY of your old oil out. They may have just changed the filter, added a quart, and sent you over the river and through the woods.
RAY: And wouldn't that frost your girdle?
TOM: When you remove the drain plug, the vast majority of the oil pours out very quickly. Within a minute, it's down to a trickle. And at that point, you've got--at most--half a pint still in the engine. And that's not enough to make the other four "new quarts" look dirty.
RAY: Besides, it would be difficult to stop the majority of oil from gushing out during that first minute. It would be a horrible mess... like trying to cap the milk bottle while you're holding it upside down and pouring it. The boiling hot oil would run right down their arms. And even these neanderthals wouldn't subject themselves to that sort of unpleasantness just to save two bucks.
TOM: So if the oil really looks dirty, there are only two possibilities. One is that they didn't even get close to letting all the oil drain out (which, as we said, is difficult even for a lazy person to do). Or, they changed your filter, dumped in one new quart, and charged you for the whole oil and filter change.
RAY: So if I were you, I'd take two actions. One, I'd never go back to that place because they're either very lazy or crooked. And two, I'd call the Attorney General's office and tell them that if they're ever thinking about doing an automotive repair "sting" operation, you have a very promising candidate for them.
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