Coolant/ anti freeze

[ck80]

Good to know. I am just using our reverse osmosis tap water from now on, used it this last time, pay enough for it as is. It seems there is draw backs, no matter which water is used. The waterless Coolant isn't strong enough for our Winters. Turbo Power is the one selling Deionized Water up here as the stuff to use in your radiator.

And, you know, if you had a plastic/aluminum radiator, an all aluminum block, all aluminum heads, proper gaskets and the like... well then you're probably OK. Carbonic acid doesn't have significant interaction with aluminum usually. I doubt they're doing the inquiries on each customer's build though, and I'd guess they just see it as a chance at an upsell. Then again, even an aluminum engine with steel shim gaskets may see a pitting/erosion issue over time somewhere you don't want it so....

 

[olds307 and 403]

I have a mix of Deionized, hard scale tap water and reverse osmosis. Yeah, the new motor will get a flushed system and new 50/50 with RO water.