Nissan's Cool Paint Claims 41˚F Reduction in Cabin Temperature

Nissan claims it is co-developing an automotive paint that can lower the temperature inside a car’s cabin by up to 41˚ F(5˚ C).

Dubbed Cool Paint, the coating has been developed in partnership with radiative cooling specialist Radi-Cool and incorporates metamaterial, which are synthetic composite materials with structures that exhibit properties not usually found in nature.

One of the major advantages is that lowering interior cabin temperatures in hot weather will reduce energy consumption used by the vehicle’s air-conditioning system and extend potential range in both battery-electric and internal-combustion-engine vehicles.

Nissan proved the paint’s performance during an initial test on a Nissan NV100 service shuttle operated by All Nippon Airways working out of Tokyo International Air Terminal in Haneda. With its large, open tarmac, the airport provided the perfect environment to conduct real-world evaluation of the paint’s performance under an exposed high-temperature environment.

Initial results show that when parked side-by-side under the sun, a vehicle treated in Nissan’s cool paint has shown up to a 54˚F (12˚C) reduction in exterior surface temperatures and up to 41˚F cooler interior compared to a vehicle featuring traditional automotive paint. The paint’s cooling performance is particularly noticeable when a vehicle is parked in the sun for an extended period.

Nissan’s metamaterial embedded within the paint features two microstructure particles that react to light.

One particle reflects near-infrared rays in the sunlight that would typically cause molecular level vibrations within the resin of traditional paint to produce heat. However, it is the second particle that enables the main breakthrough. It creates electromagnetic waves that counteract the sun's rays, redirecting the energy away from the vehicle into the atmosphere. Combined, Nissan claims the particles reduce the transfer of heat into surfaces such as the roof, hood, doors and panels.

Leading the development is Susumu Miura, senior manager and expert at the Advanced Materials and Processing Laboratory, Nissan Research Center. He says: “My dream is to create cooler cars without consuming energy. This is especially important in the EV era, where the load from running air conditioning in summer can have a sizable impact on the state of charge.”

Miura and his team have tested over 100 samples and are currently evaluating a paint thickness of 120 microns, approximately six times thicker than typical automotive paint. They have confirmed resistance to salt and chipping, peeling, scratches and chemical reactions, along with color consistency and repairability. As development progresses, Miura and his team continue to explore thinner options that deliver the same level of cooling performance.

Miura sees strong potential, particularly for light commercial vehicle applications such as vans, trucks and ambulances that spend most of the day out driving.