More than likely 4.5 quarts. Park the vehicle on a level surface. Drain the oil and replace the filter. Pour in 4 quarts of the correct weight oil. Start the engine a let run for 1 minute. Shut it down and wait 15 minutes. Check the oil level and add until it is at the full mark. Do not overfill. You now positively know the capacity.
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According to the 2006 Lincoln Zephyr Owner Guide :
With engine oil filter change :
( 6.0 U.S. quarts of engine oil ) is used in the 3.0 liter DOHC " Duratec " V6
According to the 2006 Lincoln Zephyr Owner Guide : ( 17.5 U.S. gallons / 66.2 litres )
According to the 2006 Lincoln Zephyr Owner Guide : ( 17.5 U.S. gallons )
The 2006 Lincoln Navigator owners manual shows : 7 quarts WITH FILTER CHANGE for your 5.4 L 3V engine
According to the 2006 Lincoln LS Owner Guide : With engine oil filter change ( 6.5 quarts )
Under the dash.
In a 2006 Lincoln Zephyr : The fuse panel is below and to the left of the steering wheel , by the brake pedal ( it has a cover on it ) Also , the Power Distribution Box ( which is " live " ) is located in the engine compartment between the battery and the drivers side fender
For a 3.9 liter V8 engine in a Lincoln LS : With engine oil filter change : You don't mention the year , but looking at the owner manuals 2000 to 2002 models ( 6.0 U.S. quarts ) 2003 to 2006 models ( 6.5 U.S. quarts )
According to the 2006 Lincoln Navigator Owner Guide : With engine oil filter change : ( 7.0 U.S. quarts / 6.6 litres of 5W-20 engine oil )
According to the 2006 Lincoln Navigator Owner Guide ( 5W-20 ) * with engine oil filter change , 7.0 U.S. quarts / 6.6 litres of 5W-20 engine oil
" regular " unleaded , 87 octane ( according to the Owner Guide )
3.2 quarts with filter and 3 quarts without filter.
According to the 2006 Lincoln Navigator Owner Guide : With engine oil filter change : ( 7.0 U.S. quarts / 6.6 litres of 5W-20 engine oil )