Originally posted by mazdamazda

by the way, if this is as simple as it sounds, how come car manufacturers didn't just adjust their ECUs to do exactly what this post-combustion devices claims?
Car manufacturer CAN adjust their car's ECUs to do exactly what these devices are doing. The reason why they don't is because they have to make sure their cars run well, smooth and RELIABLE even when their owners/drivers put regular gasoline (low octane) in their tanks.

Running an engine too lean can make it overheat too.