Kind of oil for 1999 Ford expedition?

The recommended oil type for a 1999 Ford Expedition depends on the engine it has. There were a few different engines offered that year. To know for sure, you need to check your owner's manual or the sticker located under the hood.

However, generally speaking, a 1999 Ford Expedition likely uses 5W-30 motor oil. This is a common viscosity for many vehicles of that era. The owner's manual will specify whether a higher viscosity, like 10W-30, is acceptable in certain temperatures.

Crucially, the owner's manual will also specify the oil's API certification (like SM, SL, etc.). Make sure to use an oil that meets or exceeds the specified API certification. Using the wrong oil can seriously damage your engine.

Don't rely solely on online information. Always check your owner's manual for the definitive answer.