Toyota, as does Nissan and Honda, uses an ethylene glycol antifreeze base with OAT and a stiff dose of phosphates for hybrid corrosion protection. These three automaker antifreeze formulations are essentially equivalent, differing only in the marker dye color used - Red for Toyota, Green for Honda, and Blue for Nissan. Consider them interchangeable. None of these antifreezes contain any silicates. As far as I know, there are no equivalent aftermarket passenger car versions of this coolant configuration in the U.S. There are two alternate technologies that shouldn't cause harm. G-05 is ethylene glycol with OAT and reduced level silicates for hybrid corrosion protection.
DEX-COOL(tm) and the various GM-unlicensed dexclones are ethylene glycol and OAT as the sole corrosion inhibitor. I'm nearly 23 months into a fill of WalMart SuperTech "All Makes Extended Life" (a dexclone provided by Prestone) in my '03 Sonata's V6 aluminum cooling system. On a 4 1/2 hour trip to Las Vegas last week in 113 degree heat, the temperature gauge needle never budged from its customary warmed engine spot even while climbing several extended 4% grades (nearly ten miles in one case) at 70 mph with the air conditioner roaring away full blast in "Arctic Blizzard" mode. Good stuff and only $6.88/gallon. If you're still under OEM warranty or extended service contract provisions, though, better stick with the Toyota brew to avoid hassles with the dealer. If you do decide to experiment, flush ALL the current coolant out with distilled water before making a product substitution. Dilute the new brew only with distilled water. Introducing hard water minerals into a cooling system should be a capital offense.
