I was losing sleep over this last night, well not really, but you know what I mean, so I looked at my bottle of Dex Cool, and went to the Havoline web site, its Silicate free! Extended service intervals are made possible through a patented organic acid corrosion inhibitor system which eliminates the need for silicates, phosphates, borates, nitrites, and amines. The elimination of these additives is significant because many of them are abrasive to water pump seals.

Now I can relax again, I reccomend it highly, I have it in everything I own, and it stays so clean, of course I use distilled water as well.

I used to use distilled water all of the time, but now I change my coolant so frerquently that I don't bother.

Dave at KDR in my last visit stressed in NOT using Dexcool...if i recall correctly, it has a negative effect to our O-rings..

< Perhaps he wasnt aware it was silicate free? Its made from the same ethylene glycol base as regualr antifreeze, all it offers is some additives. Pretty much all new cars now come with long life antifreeze. I really cannot see how this can be bad for a rotary? Im willing to bet the new RX-8 also has long life antifreeze. Im not saying im going to ignore coolant chage intervals and leave this in for 100,000, but im sure it doesnt have a negative effect for normal use. And again, its made from the same base as all other antifreeze, besides those enviormentally friendly ones like Sierra, which CAN be bad for some engines.

I have the "100,000" mile Dex in my S-10 and it keeps it pretty cool, but the bad thing is if it gets to the air, via water leak or bad seals, it turns to mud. I asked the Chevy dealership on this and they do state it will go to mud if left unnoticed or cared for. Just some FYI if considering running this.