What kind of motor oil weight should you put in your 1987 bronco 2.9L engine?

The recommended oil weight for a 1987 Bronco with the 2.9L V6 engine depends on the operating temperature. Your owner's manual is the best source for this information. However, 10W-30 is generally considered a good all-around choice for that engine and climate conditions that aren't extremely hot or cold.

However, if you live in an area with very hot summers, a higher viscosity like 20W-40 might be better. Conversely, in very cold climates, a lower viscosity like 5W-30 might be preferable for easier starting. Always check your owner's manual for the manufacturer's specific recommendations based on your location and driving conditions. Using the wrong weight can damage your engine.