Which grade of silicone sealant is used in high temperature applications?

• A. Blue
• B. Green
• C. Yellow
• D. Red

Answer: (D)

Temperature rating drives the choice of silicone sealant. The color coding on many brands helps you pick the right grade for the heat you’ll see. High-temperature areas—like near exhaust components, cylinder heads, or other engine hot spots—need a sealant that stays flexible and resists breakdown at elevated temperatures. The red silicone sealant is formulated specifically for those high-heat conditions, handling higher temperatures than the blue, green, or yellow grades. So for engines or exhaust areas, the red grade is the appropriate choice.