The Right Car Color Keeps You Cool on the Road

The Right Car Color Keeps You Cool on the Road

A new-found way to reduce gas consumption of your car, choosing the right car color. As it turns out, the color you choose affect how much gas a car need. It is not just depending on the engine improvement or your driving habit anymore.

Experiment on Car Color
Silver and black sedan

Applied Energy volume 88 issue 12 includes an article on solar reflective car. Researchers at the Environmental Energy Technologies Division of Lawrence Berkeley National Lab found that the car color affects its fuel consumptions, cabin temperature, and emission. The experiment done was simple but effective.

The team borrowed two identical Honda Civic sedans. They installed several measuring instruments and parked the cars under the sun. The chosen car colors were black and silver. The car parked for one hour without air conditioner. It then continued with 30 minutes cool down with air conditioner running at full blast. The researchers did it for five identical soak-coal cycles.

Researchers collected data from measuring instruments on several places at the car. Such temperature at cars’ roof, dashboard, ceiling, windshield, seat, door, cabin air and vent air.

The experiment investigated several focuses. First, it would estimate fuel savings and emission reductions attainable with cool coatings. Second, it would develop an energy RD&D framework (roadmap) addressing energy efficiency measures that have potential for

improving the air conditioning performance of cars. Third, initiating development of a database of cool colored coatings for cars with measurements of solar spectral reflectance and thermal emittance of over 180 car coatings.

Solar Reflectance on Car Color

Solar reflectance on car color

The solar reflectance index (SRI) is a measure of the constructed surface’s ability to reflect solar heat, as shown by a small temperature rise. It is defined so that a standard black surface (reflectance 0.05, emittance 0.90) is 0 and a standard white surface (reflectance 0.80, emittance 0.90) is 100.

In simple definition, SRI is an indicator on how hot something are likely to become when solar radiation is incident on its surface. The lower the SRI, the hotter a material is likely to become in the sunshine.

The silver Honda Civic has a higher score in solar reflectance (SR) compared to black Honda Civic. In a scale 0-1, the silver car has a score of 0.58. however, the black Honda Civic has only 0.05. As the term implies, the higher the SR, the cooler it is in the sun.

In simple term, white and silver cars can reflect as much as 60 per cent of the sun’s ray. Meanwhile dark color like black could only reflect around 5 per cent of the sun ray.

Result on Car Color Experiment

Silver car
Silver car

As we all now, dark colors especially black, absorb heat easily. Which explaining why people using black clothes tend to feel more heat from the sun. While cool colors, especially white, has the ability to reflect heat. This condition also applies to car color.

Black car absorbs much heat during the day. You may feel it the most when you enter your car when you park it outdoor. Many people tend to crank up the air conditioner to cool the inside temperature of the car down faster.

The experiment indicated that increasing the solar reflectance of the car’s shells by around 0.5 lowered soak temperature by about 5-6’ Celsius. Meaning, it allows the silver car for a lower-capacity air conditioner as well.

Thermal analysis predicts that the air conditioning capacity required to cool the cabin air in the silver car is less than the black car. To reach 25’ Celsius in 30 minutes, it requires 13 per cent less capacity.

It is just like a devil’s circle. The raising of global temperature makes humans depending on air conditioner more and more each day. While the high gas consumption rises the global temperature.

Fuel Economy Correlation with Car Color

Fuel Economy
Fuel Economy

In automobile. Fuel economy means the relationship between the distance traveled and the amount of fuel consumed by the vehicle.

Furthermore, the experiment also reveals the correlation between car colors to fuel economy. Cool colored car shells reduce the soak temperature. Thus, it increases the fuel economy by decreasing the vehicle’s ancillary load. Moreover, it allows the use of smaller air conditioners.

United States Department of Energy suggests that “running your car’s air conditioning is the main contributor to reduced fuel economy in hot weather.” In addition, “under very hot conditions, AC use can reduce a conventional vehicle’s fuel economy by more than 25 percent.”

The number compiled in this experiment found that using ­­­cool colored car such as white or silver shell would lower fuel consumption by 0.21 liters per 100 km. it would raise fuel economy by 0.91 km L-1. Also decreasing air pollution.

Cool-colored cars produce lower CO emissions by 4.9 g km-1 (1.9%), NOx emissions by 0.0099 g km-1 (0.80 %), CO emissions by 0.031 g km-1 (0.79%), and HC emissions by 0.0074 g km-1 (0.67%).

Solar Reflecting Paint

Toyota Prius lime green 2017
Toyota Prius lime green 2017


Besides choosing white or silver car, the type of paint is also crucial. Go for solar reflecting paint. It is formulated to reflect sunlight and dissipate heat from dark colored objects. It could be called many different names. Cool paint, reflective pain, a low solar absorptance paint.

In 2017, Toyota used Thermo-Tect paint in lime green color. The Thermo-Tect paint is made without carbon black, a regular ingredient in paint that absorbs sunlight and raises the temperature of the car. Plus, Toyota added titanium oxide to the paint. It works to reflect sunlight.

Johns Hopkins University applied Physics Lab created a paint that do similar work. The paint uses glass to create a more reflective.  The team at the lab think glass, which is made out of silica, would be an ideal coating. Glass is hard, durable and has the right optical properties. The paint is made of silica and potassium silicate

Car color could be a new consideration when you pick your next wheels. Think of it as a cool way of saving the planet and gas allowance while hitting the road. Don’t you think we all need that?





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