You are correct. You are paying for 10 quarts and they are trying like heck to give you all of it.

 

I don't think they are using a master mechanic to change the oil....likely to be the low man on the totem pole. Why risk it and then have to worry about them scratching my paint or worse. Even if they promise to not wash your car it may get washed and then dried with some pos towel and then you've got some nice swirl marks.....and on and on. If they do screw something up most dealers will either not do anything and hope you don't notice or do some half *** repair and not tell you about it.
I just don't see ANY upside to letting the dealer do anything other than warranty work.

 

back in the early 60s when I was 16 I worked at a Buick dealership. I was a "lot"boy,moving cars,dumping trash, washing cars, oil changes,anything they needed done...I had no idea what I was doing. Im sure things havent changed much.

 

Grease monkeys do oil changes,