Mazda B4000 Owner's Manual page 203

2.3L engine
3.0L & 4.0L engines
When the engine is cold, check the level of the engine coolant in the
reservoir.
The engine coolant should be at the "cold fill level" or within the "cold
fill range" as listed on the engine coolant reservoir (depending upon
application).
Confirm the color and type of engine coolant before adding, to avoid
mixing incompatible products.
Refer to the service maintenance section for service interval
schedules.
Be sure to read and understand Precautions when servicing your
vehicle in this chapter.
Maintenance and Specifications
203