In the process of doing first oil change on 2017 Mustang GT (5.0). Manual says capacity is 8 qts. I got at most 5 - 5.5 qts.out of the pan when I drained it. No warning lights before. Oil pressure okay. Any ideas? Would the car run 2 - 3 qts. low without giving me some indication? At this point, I'm not sure how much oil to put back in it. Don't want to overfill.

 

If you go by the engine oil dipstick , you should be OK.

It is possible the engine does require 8qts for addl oil cooling . What does the oil pan appear like, ,does it appear to have a larger type oil pan?

 

I have a 1990 mustang and it does the same thing. The reason you're only getting 5 quarts is because there is a lot of oil in the filter. Make sure you change the oil filter when doing the oil. My cars dipstick says the oil is way too high when I first put the new oil in but it drops to a normal level once I let the car run and the filter gets full of oil