Well what kind of a transmission is it bolted up to? different transmissions hold different amounts of transmission fluid and a 6.5 liter diesel will bolt up to several different transmissions.
It all depends on what kind of car you have.
The automatic transmission used in the 1995 Ford Explorer is a ( 4R55E )
2.5 liter 4 cylinder , or the 3.0 liter or 4.0 liter V6
Depending on which model of Ford Escort , either the 2.0 liter SOHC or the 2.0 liter DOHC Zetec engine
You could have the 2.9 liter , the 3.0 liter " Vulcan " or the 4.0 liter V6 engine . They are all over head valve / pushrod designs in a 1992 Ford Ranger
For the 4.0 liter V6 ( 5W-30 ) and for the 4.6 liter V8 ( 5W-20 ) in a 2003 Ford Explorer , according to the Owner Guide
5W-30
( 5W-20 ) according to the owners manual for the 2002 Ford Escape for the 2.0 liter four cylinder engine and the 3.0 liter V6 engine
According to the 2010 Ford Escape owners manual : For the 2.5 liter four cylinder engine and the 3.0 liter V6 engine : ( 5W-20 )
For the 4.0 liter V6 engine ( 5W-30 ) For the 4.6 liter V8 engine ( 5W-20 ) According to the 2004 Ford Explorer Owner Guide
It could be a 302 ( 5.0 liter ) or a 351 ( 5.8 liter )