The maximum towing capacity of a 2012 Ford E-Series van varies significantly depending on the specific model (E-150, E-250, E-350), engine, and configuration (wheelbase, options, etc.). There's no single answer.
To find the exact towing capacity for a *specific* 2012 Ford E-Series van, you need to check the sticker on the driver's side doorjamb or consult the owner's manual. The information will be clearly stated there.