Mazda B4000 Owner's Manual page 196

6. Wipe the indicator clean. Insert the indicator fully, then remove it
again.
If the oil level is between the MIN and MAX marks, the oil level is
acceptable, DO NOT ADD OIL.
If the oil level is below the MIN mark, add enough oil to raise the level
within the MIN-MAX range.
2.3L I4 engine
SAE 5W-20
3.0L V6 engine
SAE 5W-20