Nissan’s Making Special White Paint That Can Keep Cars Way Cooler In The Sun

“White cars are cooler,” goes the common logic. Many have investigated the matter, and by and large, there seems to be something to it. But Nissan isn’t simply content to slather its cars in regular white paint. It’s developing an extra-special paint to keep cars cooler when the sun is beating down.

The Japanese automaker has been working with Radi-Cool, a company that specializes in radiative cooling products. It creates coatings which minimize absorption of heat from the sun, while radiating away as much heat as possible.

The hope is that this could have benefits to both comfort and efficiency. After all, nobody likes getting in a hot car, nor waiting for the air conditioner to bring the interior down to a less-scorching temperature. But what of the numbers?

Fear not. Nissan is doing real science here. Thus far, its efforts have netted some real gains. Its new cool paint was able to slash surface temperatures by 21.6°F, and interior temperatures by 9°F, compared to a similar vehicle coated in conventional automotive paint. That’s a significant improvement, if not game-changing. It could make a car far more comfortable to enter on a hot summer’s day.

Radi-Cool notes that an ideal coating would absorb precisely zero solar radiation, while also radiating heat away at the same time. Creating a perfect reflector isn’t really practical, but it is possible to engineer a paint to absorb less heat and radiate more compared to traditional coatings.

The new extra-cool paint works by embedding two types of “microstructure particles” in the finish. One type is used to reflect near-infrared light from the sun, reducing the amount that would traditionally be absorbed by the paint. Just like regular white paint reflects more solar radiation than darker coatings, this new extra-cool paint reflects even more again. The other type of particle is used to boost the emissivity of the paint—a measure of how effectively it releases heat as electromagnetic radiation. Effectively, the new coating releases more heat as infrared energy, keeping the car cooler.

These coatings already exist, though they are typically used on buildings, not vehicles. They are normally quite thick paints which are applied via rollers or brushes. The aim of the research effort was to create a suitable version of this paint that would work in an automotive context. That meant developing a coating that would work in a typical spray applicator as is used on automotive production lines, as well as work under a clear topcoat to meet base standards for visual appeal.

 The paint has been in development since 2021. Over 100 samples have been tested thus far. The team’s best effort has netted a paint that gets down to a thickness of 120 microns, or roughly six times that of typical automotive paint. The coating has also met requirements for resistance to scratches, chipping, peeling, and salt. Work is ongoing to reduce the coating thickness and improve its readiness for production, including developing it in different colors other than white.

It’s an interesting technology and one that could net real benefits. At the same time, its impact might be obscure enough to make its uptake unlikely, depending on cost or its practicality. Automotive paint is a very mature technology, with much work expended to create reliable, attractive coatings that last as long as possible. Making drastic changes to paint could pose real risks down the line if the new coating is not as reliable as customers hope for.

Still, it’s clear to see that Nissan is working hard to make its cars cooler than ever. In this case, quite literally.

Image credits: Nissan, Radi-Cool