if used in brakes, especially, that its flashpoint is much too low -- instead of boiling and producing brake fade on the way down Pike's Peak, it might begin to burn. Besides that, viscosity stability at an extreme temperature range is very important, and only _synthetic_ hydraulic oils might have a chance here -- but would they still be compatible with the types of seal materials needed to deal with the above problems? -- cf. the silicone DOT 5 dilemma: great in British braking systems from the 50s and 60s (including my much lamented '66 Lancia Fulvia Coupe), but bad for anything else.