* 5W-20: This is a common recommendation for many 2005 F-150 engines, especially those designed for fuel efficiency.
* 5W-30: This might be recommended for hotter climates or if your owner's manual specifies it.
Crucially: The owner's manual will also specify the oil's API certification (like SL, SM, SN, etc.) and possibly the ILSAC GF-x rating (like GF-3, GF-4, GF-5, etc.). Using the wrong oil can damage your engine.
To find the correct oil:
1. Locate your owner's manual: This is the most reliable source of information.
2. Check the oil fill cap: Sometimes, the recommended oil type is printed on the oil fill cap.
3. Check the sticker under the hood: There might be a sticker detailing recommended fluids.
Don't rely on generic advice online. Always consult your owner's manual for the precise oil type and viscosity your 2005 Ford F-150 requires.