Our vehicles are made from, and run on, petroleum. We fill up our tanks with gasoline. The plastics inside our cars are extracted from petrochemicals. The tires are molded from isoprene, an oil-derived chemical for synthetic rubber. There is a lot of oil in every car. As advanced biofuels have failed to arrive at most filling stations, and may take decades longer, every little bit of oil we can remove is worth it. Today, tire makers are chasing down a future with fewer fossil fuels by making rubber tires with bacteria and natural materials.