Lincoln 2011 MKZ Hybrid Owner's Manual page 341

COOLANT CHANGE RECORD
❑
6 years or 100,000 miles (160,000 km) - change engine and motor/electronics coolant (whichever comes first).
❑
After initial change - change engine and motor/electronics coolant every 3 years or 50,000 miles (80,000 km).
2011 MKZ Hybrid (hkz)
Owners Guide, 1st Printing
USA (fus)
Scheduled Maintenance Guide
Engine coolant
341