A few years ago I came near fisticuffs with the Manager at a quick lube (redhead). We were trying to clear up my Father in Laws Estate. Took his TrailBlazer in and they did their thing. I asked them to put back I think it was 5.5 quarts. I explained I already know when it's checked hot it's a 1/2 quart low. So the reality was they would remove about 5.5 quarts.
I finally won the argument but it was insane that he could not understand by popping the drain plug and letting it drain for one minute MAX it does NOT get 6 quarts out and it would be overfull with 6. Finally he agreed to me signing 5.5 quarts was my responsibility. Next morning it was right on the FULL mark.
My last and only time EVER at a quick lube.