[DRIVER_X]

This is a pretty important subject. I am amazed this thread has so few posts.

Here is my 2 cents on the subject..

I currently have over 165k on my 04' Prii. Before I got my car in July 04', I drove a combined 70k on 3 leased 04' Prius.

I found ALL, I stress again, ALL of the dealers in my area are pretty ignorant about the car. If you are a dealer tech and you are reading this I just want you to know I don't mean to offend you.

.. I never changed my coolant not because I don't want to maintain the service schedule... I WON'T do it because I don't want my car to be a Guinea Pigs for the 'supposedly' highly Training Prius Tech! I spoke to many shops in my area, everyone of them 'knows' what to do but everyone of them is telling me a different way on how to do it right.. for starter, half of them are sure the invertor/elec. motor coolant is part of the engine cooling system.. half of them 'think' they are separated.. well?? Which one is it?

I don't claim to know about the stability of the long life fluid made by Toyota, however Knowing somewhat the design for Prius, I see very little chance the exhaust or engine oil can seep through into the cooling system like a 'normal' gasoline engine because of the substantially lower stress on the engine. Premixed with de-ionized water at the factory, I also see very little chance the coolant in the system can corrode anything prematurely. On the other hand, I can totally see a dealer tech not knowing what to do and ending up left behind pockets of air in the system.. AND adding tap water with questionable quality into the cooling system which WILL MOST DEFINITELY leaves behind calcium/chlorine in your cooling system. Worst yet, they might offer to 'flush' the system with machine that will basically 'vacuum' the coolant in the system out, which COULD potentially putting unnecessary stress on the head gasket or seals..

My advice, if you know someone who really really knows what to do.. change your coolant at 100K. If not, don't change it until you find a qualified person to do it.. I am here to tell you, my coolant in both reservoirs are as red and as clean as the day I got my car.. I'll take my chance here.. Until I am comfortable enough with the tech. I won't change it!