You don't..
The computer controls it.
http://www.guzzle7pt3.com/rdiff.php
Overheating, oil in the water of radiator, water in the oil. Less power.
Failsafe engine mode
no
Click on the link below Click on Owner Guides The Ford F-250 , 6.0 liter diesel supplement will have a chart of oil grades / temperature range
Not 100% sure on an 05 but on the 01 it is in the engine bay right in the centre of the firewall.
According to the 2005 Ford F-150 Owner Guide : The 4.6 liter V8 engine takes ( 6 quarts / 5.7 liters of engine oil ) with engine oil filter change
yes you can
to reset "check engine light"- (on '05 freestyle) remove the negative cable from the battery for at least 20 min. It worked for me
According to the 2005 Ford Expedition owners manual : The 5.4 liter 3V , V8 engine takes : With engine oil filter change : ( 7.0 quarts / 6.6 liters of engine oil )
With engine oil filter change : 5 quarts ( 4.7 liters ) of 5W-30 for the 4.0 L - V6 engine and 6 quarts ( 5.7 liters ) of 5W-20 for the 4.6 L - V8 engine ( according to the 2005 Ford Explorer Owner Guide
With engine oil filter change ( 5 quarts ) according to the 2005 Ford Mustang Owner Guide for the 4.0 liter V6 engine