Topic: Tetraethyl Lead

An in-depth technical discussion explains the transition from leaded to unleaded gasoline and the implementation of catalytic converters. The analysis highlights the toxic effects of tetraethyl lead and presents the theory that the removal of lead from the environment correlates with the significant drop in violent crime rates since the 1970s.

The history of leaded gasoline explains that tetraethyl lead was originally added to fuel to increase octane and prevent engine knock. A secondary effect was the lubrication of valve seats; without lead, valves could weld themselves to the engine head. The transition to unleaded fuel required the development of hardened valve seats and synthetic lubricants to prevent engine failure.