Oil is a renewable energy form but it takes millions of years to replace the oil.
Oil was made from dinosaurs and other fossil fuels. So any animals that die today or even humans would be turned into fossils and turn into oil millions of years down the road.
So we do need to conserve our limited supply of fossil fuels such as gasoline and natural gas because it will be millions of years before the fossil fuels are replaced.
And that's a long time.