Topping off coolant tanks

Your "considered" opinion amounts to following what others around you do. That is not a bad position in general, but it is hardly proof.

It is also not persuasive, since it ignores the changes in coolant chemistry and engine metals/rubbers/plastics in Toyota engines of the last decade. E.g., we know that over time coolant silicates precipitate out of solution and are best cleaned out of the small radiator passages as best one can -- thus the recommendation for flushes. But guess what ? SLLC does not have silicates so the primary reason to heed your 50 years of experience is now irrelevant.

My understanding of coolant chemistry is unfortunately extremely limited, but I think the following statements are true:
Ethylene glycol does not have significant breakdown
Additives provide lubrication, alkalinity, and corrosion protection.

Unless you have data that shows additive breakdown products attacking metals or rubbers/plastics, I'm inclined to think that periodic partial replacement will work just fine instead of complete replacement, particularly if the fluid stays clear. I'm not positive, so I'll consider hedging my bets until further DATA is available.

 

And yet you accuse ME of making "dogmatic" statements ??
I think you need to lighten up a bit.

It IS possible to discuss things like this without insulting the motives or intelligence of those who don't worship your considered opinion.

 

This is the dogma I object to. You have no data, only experience that technology changes has obsoleted.

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And as for my extremely limited understanding of coolant chemistry, do not take comfort since the statement should be taken in context. Compared to a chemist who makes the stuff I am a know-nothing, but compared to you I hold my own pretty well.

 

You have no idea what "data" I might have, nor do you know anything about my qualifications.
Applying negative labels to anyone who disagrees with you is just not nice regardless.

You do win when it comes to ego though; you seem to have plenty to spare.

I'm done. That comment wasn't nice either.

 

I asked you for data and you responded with obsolete experience. If you can do better, then by all means put an enlightened foot forward.