Porsche Boxster Owner's Manual page 213

3. Cover the expansion tank cap with a thick
rag. Open cap slowly and carefully and allow
overpressure to escape. Then unscrew cap
completely.
4. Only add a mixture of antifreeze and water
in equal parts, and do not exceed the "Max."
mark.
Antifreeze in coolant:
50% gives protection down to -31°F (-35°C )
60% gives protection down to -58°F (-50°C )
5. Screw cap firmly on.
6. Close service flap.
If in an emergency pure water has been added,
the mix ratio must be corrected at an authorized
Porsche dealer.
Marked loss of coolant indicates leakage in the
cooling system. The cause should immediately be
remedied at an authorized Porsche dealer.
Radiator fans
The radiator and radiator fans are in the front of the
vehicle.
Warning!
Risk of injury. The fans can start running as a
function of temperature, even with the engine
switched off.
Exercise extreme caution when working in the
area of the radiator fans.
211
Maintenance, Car Care