However, generally speaking, for a 1998 Ford Explorer, you'd likely be looking at:
* 5W-30: This is a common viscosity grade for many 1998 Explorers and is a good starting point if you don't know the exact engine. It's suitable for a wide range of temperatures.
* 10W-30: Also a possibility, especially in warmer climates.
Crucially: The owner's manual will specify the *correct* viscosity and type (conventional, synthetic blend, or full synthetic) of oil for your specific engine. Using the wrong oil can damage your engine. Check the manual first! The manual will also tell you the recommended oil change intervals.
