According to the 1996 Ford Aerostar Owner Guide : ( 21.0 U.S. gallons )
15 gallons
The 1990 Ford Aerostar and the 1989 model share a similar design and platform, as they are part of the same generation of minivans. However, the 1990 model introduced some minor updates, including improvements in interior features and safety enhancements. Overall, while they maintain a similar overall appearance and functionality, the 1990 Aerostar has subtle refinements that differentiate it from the 1989 version.
Tank 0n 91 XLT holds 21 U S gallons or 79 Litres
15.4
19 Gallons
About 15 gallons
Mine hold 17 gallons.
16.0 Gallons
20.86 Gallons
12.8 Gallons
A 1994 Ford Aerostar manual transmission will hold 1.2 liters of API GL-5 SAE 80W90 transmission oil. An automatic will hold 10 quarts if the lines are completely flushed.