English English Wikipedia has an article on:methyl t-butyl etherWikipedia MTBE stick diagram Noun methyl t-butyl ether (uncountable) (chemistry, automotive) C5H12O ; an organic compound used to increase octane ratings of gasoline, through added oxygen Synonyms MTBE methyl tert-butyl ether methyl tertiary butyl ether 2-methoxy-2-methylpropaneWikiwand - on Seamless Wikipedia browsing. On steroids.