The glycol-based brake fluid that has the highest boiling point is DOT-4.

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Multiple Choice

The glycol-based brake fluid that has the highest boiling point is DOT-4.

Boiling point is the key property that determines how well brake fluid resists vaporizing under heavy braking. The DOT rating system encodes these minimum boiling points, and for glycol-based fluids, higher numbers generally indicate formulations designed to withstand more heat. Among the glycol-based options listed, the fluid with the highest rated boiling point is DOT-4 because it’s formulated to tolerate higher temperatures than the lower DOT grades, while DOT-5 is silicone-based (not glycol-based) and DOT-5.1, though glycol-based, is not the option emphasized in this particular context. So within the glycol-based group in this question, DOT-4 is the highest-rated for boiling point, which is why it’s selected.

Boiling point is the key property that determines how well brake fluid resists vaporizing under heavy braking. The DOT rating system encodes these minimum boiling points, and for glycol-based fluids, higher numbers generally indicate formulations designed to withstand more heat.

Among the glycol-based options listed, the fluid with the highest rated boiling point is DOT-4 because it’s formulated to tolerate higher temperatures than the lower DOT grades, while DOT-5 is silicone-based (not glycol-based) and DOT-5.1, though glycol-based, is not the option emphasized in this particular context. So within the glycol-based group in this question, DOT-4 is the highest-rated for boiling point, which is why it’s selected.

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