For comparison, running an internal combustion engine causes chemical changes in the engine. There will be a reduction of certain hydrocarbons in the fuel tank,

For comparison, running an internal combustion engine causes chemical changes in the engine. There will be a reduction of certain hydrocarbons in the fuel tank, and an increase in simple hydrocarbons in the exhaust manifold, as well as a reduction of chemicals in the inlet manifold. Perhaps in future scientists will find a way to restore the chemical balance in internal combustion engine systems, thus keeping them at peak performance for longer. (In other words: The Economist's article is rather light on actual useful details. The same kind of story applies to a very wide range of topics. It might be more helpful to read the actual scientific article. ps. For some reason newspapers/magazines never provide a good reference to the actual article and you end up having to go hunting.)