Metallic additives

There are three known metallic-based octane enhancers: lead-based (tetrraethyl lead or tetramethyl lead), iron-based (ferrocene), and manganese-based. Of these, lead-based octane enhancers are no longer used, and the use of iron-based enhancers is not permitted in most countries.

Malaysia’s gasoline specification MS 118-3:2011 set a maximum lead content of 0.013 g/l. The government planned to reduce the maximum lead content to 0.005 g/l from September 1, 2025. Moreover, the Malaysian government does not set any limits on iron and manganese contents in gasoline

SGS Worldwide Fuels Survey (WWFS) results from gasoline samples taken from 2012 to 2023 show that none contained lead. Five samples from 2012, 2014, and 2015 contained iron, and some samples contained a small amount