However, since you don't have the manual, a good starting point for a 1989 Mazda B2200 with that mileage is likely 10W-30 conventional motor oil. This was a common recommendation for older vehicles.
Crucially: Check your owner's manual or the oil fill cap for specific recommendations. The recommended viscosity might be different depending on your climate (thicker for very hot climates, thinner for very cold). It's also important to check whether it specifies conventional, semi-synthetic, or full-synthetic oil.
Using the wrong type or viscosity of oil can damage your engine. Don't hesitate to consult a local mechanic or an auto parts store if you can't find the information in your owner's manual.
