At tireplus.com they offer an oil change for a mini van at the price of $22.95. I am not sure about there creditability but that is one place where you can get an oil change.
6 qt
5w30
Key on, engine off. Press gas pedal to the floor three times.
2800
20,000
5 quarts
1000 pounds about as much as a mini van
You should change the oil every 3000 miles in as 1994 Dodge Van.
From underneath
4.2 litre then check dip stick
Bottom front of engine.
In the oil pan.