I believe 5W30 is the manufacturer's recommendation for most applications. Or 10W30 would probably also be an acceptable substitute in most cases.
5w30
Oil leaks because a seal has failed.
Yes.
5 quarts
Inside the oil pan mounted on the engine block.
Answer: For a 2003 Dodge Grand Caravan, the manufacturer's recommended engine oil viscosity is 5W30. The engine oil capacity is 5.0 quarts (this applies to both 4 cylinder and V6 models.)
5 quarts
Engine idling in park.
5w20
10w30
5W-20 Oil
5w30