Toyota Prius +, W4 (EU)

Additional Notes

• The Toyota Prius+ W4 (EU) carries two separate coolant circuits: the main engine cooling system and a dedicated inverter cooling system, each with its own capacity and service interval specifications.
• The main cooling system holds 6.5 liters as a standard fill, rising to 6.9 liters when the exhaust heat recovery system is present, a difference of 0.4 liters that reflects the additional fluid volume required to circulate through the recovery hardware.
• Across all model year ranges from 2011-2021, the main cooling system capacity figures of 6.5 liters and 6.9 liters remain unchanged, indicating a consistent engine cooling architecture throughout the production span covered by these specifications.
• The inverter cooling system holds 2.7 liters across all covered model year ranges from 2011-2021, a notably smaller volume than the main circuit, consistent with the more compact thermal management demands of power electronics compared to a combustion engine.
• Under normal use conditions, the main cooling system is scheduled for a change at 90,000 km, while the first change only condition extends the initial interval to 150,000 km, after which the 90,000 km normal cycle applies.
• The inverter cooling system carries a significantly extended first change only interval of 240,000 km, compared to the 90,000 km change interval under normal use conditions, making the inverter circuit's initial fill the longest-lived coolant interval in the specifications.
• Both the main cooling system and the inverter cooling system share the same check interval of 30,000 km across all use conditions and all model year ranges from 2011-2021.
• The 240,000 km first change only interval for the inverter cooling system is 2.67 times longer than the 90,000 km normal use change interval, reflecting the lower thermal and chemical stress typically placed on inverter coolant relative to engine coolant.
• The main cooling system's first change only interval of 150,000 km is 1.67 times the 90,000 km normal use interval, a proportionally smaller extension than seen in the inverter circuit, suggesting the engine coolant degrades more rapidly under sustained operating conditions.