oil change

idk

check what your owners manual calls for, I doubt a 2002 sable requires synth. oil. it probably wouldn't hurt your car any to use it, and you'll get more life between oilchanges. it will be more costly though. and if your question was asking specifically is I/WE use synth. oil... No, I don't.

you can. synthetic oil is better for any car (except rotary engines) but is not required for any mercury.

i always use synthetic in my sables that ive had, they all had the duratec, if u drive the ohv vulcan engine u can but there would be no point it doesnt rev high enough to break down synthetic molecules

OWNERS MANUAL SAYS FULL SYNTHETIC 5-20W