Which is used as antiknock in petrol ?

Metallic pollutant used as "antiknock agent" in petrol is

Metallic pollutant used as "antiknock agent" in petrol is

The toxic metal that is used as an antiknocking agent in petrol engines of automobiles is ........... .

Which of the following is used as an antiknocking substance? Freon Glyoxal TetraethyI lead Hydrogen peroxide

Name one liquid carbon compound which is being used as an additive in petrol in some countries.