What differential lube oil is required for 91 miata?

The 1991 Mazda Miata requires a differential lubricant that meets the specifications of API GL-5. A common recommendation is to use a 75W-90 gear oil, which provides adequate protection and performance for the differential. It's important to check for compatibility with limited-slip differentials if applicable, and consider using a fluid specifically designed for that purpose if your Miata is equipped with one. Always refer to the owner's manual for the most accurate specifications.