Effect of exhaust oil, carbon deposits and heat on rear tire

[g-force_addict]

If future rules changes allow placing the exhaust outlets somewhat in front of the rear wheels

Would hot exhaust air help keep rear tires warm and grippy?
Would carbon and oil residues make the tires dangerously slippery?

[riff_raff]

Overheating the tread surface rubber compound of a tire by blowing hot engine exhaust gas onto it would make the tire "dangerously slippery". Race tires use tread surface rubber compounds that are designed to perform best at a certain temperature. And there is enough heat generated within the tire structure after just a few corners to get the tread surface up to the optimum temperature it was designed for.

Small amounts of carbon particulates in the engine exhaust would not likely have much effect on the tire grip. But if the engine started to leak small amounts of oil into the exhaust flow this would cause big traction problems if it coated the tire tread surfaces.

[PlatinumZealot]

If future rules changes allow placing the exhaust outlets somewhat in front of the rear wheels

Would hot exhaust air help keep rear tires warm and grippy?
Would carbon and oil residues make the tires dangerously slippery?

RedBull actually did that in 2011. They used a portion of the exhaust gas (the portion that did not go under the diffuser) to heat the inboard side of tyres. It took them a while to master it, but before they did they had atrocious tyre wear.