Collection: Automotive Thermal Insulation and Heat Barriers

Automotive insulation keeps heat out of a car by slowing the rate at which heat moves through a panel, and R-value is the number that measures it. The higher the R-value, the less heat from the engine, exhaust and sun reaches the cabin. R-value rises with thickness, so the space behind a panel sets the limit on what a material can do. Comparing R-value per inch is the fastest way to line up insulations of different thickness.

The best insulation for a car depends on where it goes, and R-value per inch is the quickest way to compare the options. Luxury Liner Pro and Heat Wave Pro suit the floor, Mega Zorbe and 3M Thinsulate SM400L suit doors and roofs, and Mega Block suits the hood and engine compartment. Heat Wave Pro is a more flexible alternative for the hood and engine compartment. Our guide on how to choose the best automotive insulation covers the choice in more depth.

Luxury Liner Pro is the best insulation for a car floor. It fuses mass loaded vinyl to a closed cell foam layer in one 3/8 inch sheet with an R-value of 4.45 per inch, so it slows heat coming through the floor pan and reduces road and engine noise at the same time. Heat Wave Pro is the alternative, a foil-faced jute blanket with an R-value of 3.91 per inch that carpet installs directly over. Both install on the cabin side of the floor pan.

Our insulation packages cover 12 to 20 square feet for the hood or firewall and 24 to 48 square feet for the roof, and floor coverage varies by vehicle. The table lists each package size by area. The vehicle square footage calculator works out the exact number for a specific car, and the recommendation tool turns that number into a material list.

Yes, adding a sound deadener before installing car insulation is a great way to get the most out of your install while the upholstery is out. A layer of Damplifier Pro or Spectrum goes on the bare metal first, and the insulation goes on top. That order gives heat one more layer to pass through, and the deadener adds structural sound reduction that insulation alone does not provide. If you are unsure whether a sound treatment should be part of your project, the recommendation tool builds a material list for heat only or for heat and sound.

Car heat insulation resists the heat that passes through it, while a car heat shield reflects heat away from a surface. Insulation such as Heat Wave Pro and Luxury Liner Pro is rated by R-value, and a higher number means more thermal resistance. Heat shields such as Mega Block, Thermal Block and Radiant Shield use a reflective foil face to reflect radiant heat, which suits the exhaust tunnel and engine bay. Mega Block's foil is rated up to 1000°F. That rating requires a 2 inch gap from the heat source. Radiant Shield's foil is also rated up to 1000°F. Many builds use both. At the air intake, for example, a shield keeps hot engine air away, and this guide on why an intake heat shield improves engine performance explains the payoff. If you've learned you need a heat shield, we have more options in our heat shields collection.

3M Thinsulate SM400L, Mega Zorbe and Heat Wave Pro are the best insulation choices for car doors and roofs. 3M Thinsulate SM400L insulates door panels, headliners and pillars. Mega Zorbe is a lightweight melamine foam that fits inside door cavities and under roofs. Heat Wave Pro handles low-clearance headliners where thickness is limited. When a roof has room to spare, as in a van, 3M Thinsulate SM600L adds more thickness. For door trim that rattles, OverKill Pro closed cell foam holds the panel snug against the metal.

Yes, car insulation keeps a car warmer in winter by holding cabin heat in. That saves energy, because a car's heating system does not have to work as hard to keep the cabin warm on a commute. The same R-value that slows engine and sun heat in summer slows warmth escaping through the floor, roof and doors in the cold. Luxury Liner Pro or Heat Wave Pro on the floor and Mega Zorbe in the doors and roof cover the main areas.

Yes, Second Skin car insulation materials meet vehicle fire standards. FMVSS 302 is the U.S. flammability standard for vehicle interior materials. Heat Wave Pro exceeds it. 3M Thinsulate SM600L and SM400L pass it. Thermal Block passes it.