Based on my experience working for Mobil I wouldn't trust places like that to change your oil. At the end of every oil change we would ask that the person start the car to check for leaks. Whether the oil pressure is up or not whether you have an oil pressure gauge or not in your cars cluster they still would say "lights out, pressure's up". Then they pull your oil dip stick to then show you your oil. Well if there was little to no oil on the stick the tech would reach down below for oil that spilled whether motor oil or gear oil and put it on the dip stick and then show the customer that it was "full". If they couldn't do that they would bring the dip stick up so the oil would roll to the full mark. Those places also don't give you the amount of oil your car needs. There was a time at Mobil that the manager was telling us were missing oil we need to make it up and cut back on the customer. So if your car took 4 qts. you were actually getting 3.5 qts.

True story... I worked there for about 6 months or more. As a tech, I made sure the customer got the amount of qts of oil their car took. I didn't cut back. I did play any games or pull any tricks. I don't like being shady and I did my job the right way whether the manager liked it or not he wasn't watching over my shoulder. In fact the print outs would say 4qts and he would put 3.5 on my paper work but I would always check the back sheet. Leave the 3.5 on the paper work and give the customer the .5 more the deserved.