On the 2 litre engine (2005 and later), 13mm.
15mm
15mm
12 millimeter
the bolt is 15 mm
5/8
11/16th
5/8"
5/8"
Use a proper size box-end wrench or socket to remove the oil drain plug
Mine is 12mm wrench, but some are different.
13 mm on my 2002 Ford Ranger 4.0 XLT
Every car and truck is different however most ford vehicles have a 13mm or a 15mm drain plug. I would use a wrench to remove and install the drain plug since it is easy to damage the pan if it is overtightened. If the plug has been replaced, it may have a different size.