If it wasn’t for Toyota sealing the coolant passages on their engines with RTV, I would say Prestone is fine. However, Toyota Pink uses sebacic acid as the OAT, and Prestone uses both 2-EHA and sodium neodeconate(also a sebacic acid derivative) and the MZ/UR engines already leak coolant from the valley plate so it’s a draw.
That said, I have Prestone in a 3MZ-FE powered Sienna. Almost 4 years since the valley plate reseal, no coolant loss besides evaporation in the reservoir.
That said, I have Prestone in a 3MZ-FE powered Sienna. Almost 4 years since the valley plate reseal, no coolant loss besides evaporation in the reservoir.