The 4.0 liter OHV , V6 engine in my 1995 Ford Explorer holds :
With engine oil filter change :
( 4.7 litres / 5.0 U.S. quarts of 5W-30 engine oil )
I assume your Aerostar would be the same
five quarts.
According to the ( 1996 ) Ford Aerostar Owner Guide : With engine oil filter change : The 4.0 liter V6 engine takes : ( 5.0 U.S. quarts / 4.7 liters ) * 5W-30 is the PREFERRED oil
According to the 1996 Ford Aerostar Owner Guide : ( 5W-30 ) is the preferred oil
10w30
Ford Aerostar
1part by volume of oil to 40 parts by volume of gas.
On a 1996 Ford Aerostar , 4.0 liter V6 engine : The oil pressure sending unit for the oil pressure gauge is on the drivers side of the engine below the power steering pump
A 1993 Ford Aerostar would have come from the factory with ( 5W-30 )
5W-30
4 Quarter of Oil 10/40
The 1997 Ford Aerostar oxygen sensor is screwed into the exhaust pipe. It is about even with the rear of the oil pan.
On a 1989 Ford Aerostar : I believe the oil pressure sending unit for the oil pressure gauge on the 4.0 liter EFI , V6 engine is on the drivers side of the engine below the power steering pump