The schedule states 150k for the inverter coolant change and the engine coolant at 100k. I did the engine coolant at 100k and now I’m at 110k. Should I just do the inverter coolant now? My gen 3 Prius required both coolant systems changed at 100k. What is so different about the Prius C to wait another 50k miles for the inverter? Thanks
I don’t think there is a difference between the models: the Warranty & Maintenance Guide books for the 2010 (PDF) and 2015 (PDF) Prius, for example, have the same footnote as the book for the 2012 Prius c (PDF): “Initial inverter coolant replacement at 150,000 miles/180 months. Replace every 50,000 miles/60 months thereafter.” I can only speculate about why Toyota believes their Super Long Life Coolant lasts longer in the inverter cooling system; possible factors are that the inverter coolant doesn’t get as hot—“Controlled at 65°C (149°F) or less” for the inverter coolant, versus “75 to 100°C (167 to 212°F): After warming up” for the engine coolant, according to the Repair Manual—and has less surface area in contact with other parts.
Toyota Canada issues a single maintenance schedule booklet for all their vehicles, and says to change both engine and inverter at 160K kms or 10 years, whichever comes first. I suspect they just missed the footnotes in the US schedule?? And then, if I look at the side wall of my inverter coolant reservoir, there's a sticker saying to not change till 150,000 miles, lol.
