I'm luck enough to have my own lift, handy with 4 cars. Obviously I do my own oil changes and drop used oil at Auto Zone. For my '06 GT and my wife's '08 Miata GT I use Pennzoil Ultra Platinum 5W20. Hard to find, so I order it from Amazon. Over $35 shipping is free. Works for me. For the '85 Mustang GT and '68 Camaro 'Vert, they just get Pennzoil Dino oil 10W40. These cars get driven little, so I change them once a year in the fall.

 

My owners manual calls for 8 quarts of oil for a 2015 Mustang 5.0 change - is this correct? The garage only added 6 quarts