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
From underneath
You should change the oil every 3000 miles in as 1994 Dodge Van.
1000 pounds about as much as a mini van
4.2 litre then check dip stick
Bottom front of engine.
In the oil pan.