* Check your owner's manual: This is the most reliable source of information. It will specify the correct oil type (e.g., 5W-30, 10W-30) and viscosity.
* Look for the sticker under the hood: Many vehicles have a sticker under the hood near the radiator or engine that lists recommended fluids, including oil.
* Common oil types: Many 1998 Ford Rangers used 5W-30 or 10W-30 oil. However, the *weight* of the oil is crucial and should be determined by your owner's manual or under-hood sticker. Do not rely on this alone.
* Oil type (conventional, synthetic blend, synthetic): The owner's manual may also specify whether conventional, synthetic blend, or full synthetic oil is preferred. Using a higher-quality oil (synthetic blend or full synthetic) can often extend engine life and provide better performance, but it's not always strictly necessary.
In short: Do not attempt to change your oil without first consulting your owner's manual or the under-hood sticker. Using the incorrect oil can damage your engine.
