What kind of motor oil do you put in a 1999 Ford Expedition?

The type of motor oil for a 1999 Ford Expedition depends on the engine it has (4.6L V8 or 5.4L V8) and the climate where you live. However, consult your owner's manual for the most accurate and up-to-date information. The manual will specify the recommended viscosity (like 5W-30 or 10W-30) and API certification (like SM or SN).

Generally, for a 1999 Expedition, a conventional 5W-30 or 10W-30 motor oil meeting the specified API standards was likely recommended. However, using a higher-quality synthetic blend or even full synthetic oil is generally acceptable and can offer some benefits like better performance and longevity in harsh conditions. Again, check your owner's manual for specifics.

Never use an oil that doesn't meet the specifications outlined in your owner's manual. Using the incorrect oil can damage your engine.