Gasoline is refined from crude oil and so as long as we have crude oil we can make gasoline.
We have around 52 years of crude oil left on earth as of now but I'm sure that eventually there may be even more crude oil found within that time frame.
As for crude oil we have around 1.7297 trillion barrels of crude oil left on earth as of 2020 which is still quite a bit of crude oil.
However the good news is that a lot of cars are using electricity to drive and also we have ethanol based gasoline that makes the gasoline go further.
So since we have plenty of renewable ethanol that gets mixed in with the regular gasoline we will make the gasoline we do have last longer.
It's unlikely that we would run out of gasoline in my lifetime at least and I'm already 33 years old as of now so I would be in my 80s anyway by the time we get near depletion of gasoline and crude oil.
But it's likely there are still a lot more crude oil beneath the earth because the earth is a vast and really large space.
We just have to drill in more areas and maybe drill even deeper to find more oil to make gasoline.