2026-07-21 · 4 min read
Toyota Prius Coolant Guide Malaysia — Two Coolant Loops
Prius has engine coolant and a separate high-voltage inverter coolant loop. Never mix them. Neglect causes inverter overheating — a very expensive repair.
Prius has two cooling circuits — engine coolant and inverter coolant. Both use Toyota SLLC (pink OAT). Change every 4 years. Never let the inverter coolant run low — inverter overheating causes system shutdown and expensive repairs.
Coolant Service
- Engine coolant flush: RM 100–160
- Inverter coolant flush: RM 100–160 (separate circuit, separate reservoir)
- Do both at same service for convenience — use Toyota SLLC for both circuits