Transformer oil's primary functions are to insulate and a cool a transformer. It must therefore have high dielectric ,strength,thermal conductivity and chemical stability, and must keep these properties when held at high temperatures for extended periods. Typical specifications are: flash point140 °C or greater, pour point −40 °C or lower, dielectric breakdown voltage 28 kV (RMS) or greater.
Valvoline™ Outboard Gear Oil 80W-90 is a marine environment extreme pressure gear oil suitable for use in the gearboxes of most boats fitted with an outboard engine, stern drive unit, and other marine uses. Valvoline Outboard Gear oil provides increased protection against rust, corrosion, oxidation and wear under severe conditions.
Valvoline heat transfer oils are developed to withstand elevated temperatures and are recommended to be used for non-pressured closed heat transfer systems that operate at temperatures that go between -10 0C to + 320 0C