Suppose you had an internal combustion engine that functions well in 20.9% O2, but very poorly in 19.2% O2. Then a mechanic shows up a lever you can pull that

Suppose you had an internal combustion engine that functions well in 20.9% O2, but very poorly in 19.2% O2. Then a mechanic shows up a lever you can pull that alters the way the engine intakes and processes O2. You move it a bit, and all of a sudden, the engine now functions just as well in 19.2% O2 as 20.9% O2. Now imagine that the engine can measure its own performance, and can move the lever itself ...