Thank you for writing in. The engine oil capacity for a 2002 Mercury Sable is 4.5 quarts, or 5.5 quarts with a new oil filter as well. You should be changing your oil filter as well, so plan on using 5.5 quarts. Good luck!
〉 Answered on Feb 4th, 2019 by Jessica Howe, Automotive Expert & Coach at AskPatty.com