look in your owners manual but probably 5w-30.
V8 hemi
Should be 5 quarts with a new filter.
5W30 It is written on the oil filler cap.
The 2000 Mercury Mountaineer owners manual shows ( 5 W 30 ) - for the 4.0 L - SOHC - V6 engine and the 5.0 L - V8 engine
Yes it will bolt right up to a V8.
Too much! Buy a V8
A 2000 Dodge Durange with 4.7L V8 engine requires 6.0 quarts of oil when you're doing a filter change.
I calc'ed my '91 V8 Formula Firebird to be about 18 mpg.
castrol oil 5w30
My 2000 Sierra with 5.3 liters V8 needs 6 1/2 quarts of oil
10w30 the recommended weight.
10W30 would be recommended.