Fossil Fuels

Why was lead added to gasoline and why is lead-free gasoline used in cars?

Tetraethyl lead was used for more than 40 years to improve the combustion characteristics of gasoline. It reduces or eliminates “knocking” (pinging caused by premature ignition) in large high-performance engines and in smaller high-compression engines. It provides lubrication to the extremely close-fitting engine parts, where oil has a tendency to wash away or burn off. However, lead will ruin and effectively destroy the catalyst presently used in emission control devices installed in new cars. Therefore, only lead-free gasoline must be used.


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