Function of glycol in motor gasoline\nGlycol added to petrol primarily acts as a/an ______ agent.

Introduction / Context:
In cold climates, carburetor and intake system icing can disrupt fuel–air mixing. Certain additives mitigate icing by altering water phase behavior and vaporization characteristics.

Given Data / Assumptions:

• Additive is a glycol (e.g., ethylene or diethylene glycol derivatives).

Concept / Approach:
Glycols act as anti-icing agents by depressing the freezing point of water and promoting dissolution of moisture that could otherwise crystallize as ice in carburetors or throttle bodies. They are not primary anti-knock agents (which include high-octane blending components), nor are they gum inhibitors or dewaxing agents.

Step-by-Step Solution:

Verification / Alternative check:
Historical winter gasoline formulations include anti-icing additives (alcohols/glycols) to prevent carburetor icing.

Why Other Options Are Wrong:

• Anti-knock relates to octane improvers.
• Anti-gum agents are antioxidants/detergents.
• Dewaxing pertains to middle distillates, not gasoline.

Common Pitfalls:
Assuming one additive provides all functions; modern gasolines use additive packages with distinct components for each role.

Final Answer:
Anti-icing