To improve the heat exchange between the rim and the tire, a sort of liquid glass with black opacifying pigment is used on the rim which is used to improve thermal conductivity. The only world producer of this innovative product is Nanoprom and the product is called Polysil. It is an atomic silicon-based coating with revolutionary characteristics that allows the protection of the substrate by reconditioning the surface structure. With a layer of a few microns with high surface hardness (9H), the surfaces also have a high resistance to abrasion. This "liquid glass" weighs 95% of a normal paint and has a temperature resistance of 1100 ° C. Currently the paintwork of a Formula 1 wheel weighs from 65 to 85 grams. Thanks to this product, the painting weighs only 5 grams and in addition to improving the thermal conductivity it has given an improvement of 3 points to the CFD as less turbulence is generated in races where the track was not very hot to increase the heat exchange between the rim and The inner part of the rim was also coated with Polysil. This new treatment is aimed at increasing the temperature on the inner face of the rim. through an increase in gloss, the refraction of heat increases, decreasing its dissipation, while it does not prevent the heat resulting from braking from passing inside. This product, this season has been used by Mercedes, Red Bull, Ferrari and McLaren but surely in the next season it will also be used by many other teams.

[Source: http://www.f1analisitecnica.com/2013/12/modifiche-tecniche-top-e-flop-della.html?spref=tw&m=1]