Why do NASCAR drivers weave side to side?

Answer 1

At the beginning of a race or a restart after a caution, Nascar drivers will weave their cars side to side to clean off as much debris as possible from their tires. Also, this process will heat up the tires for a better grip.

Answer 2

They do this so they don't get a fuel block. Also to keep their tires clean before a restart.

Answer 3

To heat up the new tires for maximum traction