What is the smoke that comes from tire burnouts made of chemically?

What is the smoke that comes from tire burnouts made of chemically?
A2. The smoke that comes from a 'burn out' is fairly accurately named, for the tire becomes sufficiently hot as to approach its ignition point. Some of the compounds in the tire pyrolyze before others, and these generate the 'smoke'. The softer parts of the rubber are spread on the road.
So pyrolysis products ise the short answer.
In this enterprise, you are putting several tens of kW into the tire.