You don't say which engine you have , so I have included everything :
According to the 2003 Ford Ranger Owner Guide :
With engine oil filter change :
The 2.3 liter four cylinder takes ( 3.8 litres / 4.0 U.S. quarts of 5W-20 )
The 3.0 liter V6 takes ( 4.3 litres / 4.5 U.S. quarts of 5W-20 )
The 4.0 liter SOHC , V6 takes ( 4.7 litres / 5.0 U.S. quarts of 5W-30 )
( 4.5 quarts of engine oil ) with oil filter change for the 3.0 liter V6 ( according to the 2003 Ford Ranger Owner Guide )
According to the 2003 Ford Ranger Owner Guide : For the 3.0 litre V6 engine : With engine oil filter change ( 4.3 litres of engine oil )
gear oil if it has posie put in the adtivive
According to the 2003 Ford Ranger owners manual : 2.3 L and 3.0 L engines - the preferred oil is ( 5 W 20 ) 4.0 L - SOHC - V6 engine - the preferred oil is ( 5 W 30 )
The 2003 Ford Ranger owners manual shows : ( 4.5 quarts with filter change ) for the 3.0 L - V6 engine
Motorcraft ( FL820S ) according to motorcraft . com
5 quarts ( 4.7 liters ) WITH FILTER CHANGE
Where is the oil pressure sending unit on 1992 ford ranger
With engine oil filter change ( 4.0 quarts / 3.8 liters of engine oil ) for the 2.3 liter four cylinder in a 2007 Ford Ranger
10W30 is the type of oil that a 1988 Ford Ranger takes. The Ford Ranger was first produced in 1983 and discontinued in 2012.
With engine oil filter change ( 5.0 quarts / 4.7 liters of engine oil ) according to the 2001 Ford Ranger Owner Guide for the 4.0 liter V6 engine
4 or 5 quarts