However, generally speaking, a 1999 Ford Explorer would likely benefit from:
* Viscosity: Look for a 5W-30 or 10W-30 oil. Again, check your owner's manual; this might vary based on climate. Thicker oils (like 20W-50) are generally not recommended for older vehicles unless specified in the manual.
* Type: Conventional, synthetic blend, or full synthetic oil are all options. Full synthetic is generally better for longevity and performance in extreme conditions, but it's more expensive. A synthetic blend offers a good compromise between cost and performance. Conventional oil is the cheapest but may require more frequent changes. Your owner's manual might specify recommendations, but most modern oils are compatible with older engines.
Before adding any oil, consult your owner's manual. It will explicitly state the recommended oil type, viscosity, and oil capacity for your specific engine. This is crucial to avoid damage to your engine. You can often find a digital copy of the manual online through a Ford website or a third-party manual provider.
