Manufacturing a car tire requires 7 gallons of oil. 5 are raw materials to produce the synthetic rubber, while 2 gallons supply the energy required.
Lets assume the energy is produced by alternative means, that leaves us with 5 gallons of oil per car tire.
That's 5 billion gallons of oil for 1 billion tires.
There's around 35 gallons of oil per barrel. That's 142,857,143 barrels of oil.
The US produces roughly 9.5 million barrels of crude per day. It would take around 15 days to make 1 billion new tires if 100% of US oil was dedicated to the cause.
Now that I've done the maths, it doesn't seem like such a huge problem. So I concede to your point.