Premium Gasoline, Research Octane 102.7: Alkylate, Reformate, Light Cracked Gasoline and Isopentane with 2.7 cc Lead (Gulf, US 3,071,535)

Premium petrol is not made in one unit: it is blended. Gulf's 1959 recipe mixes alkylate, two cuts of reformate, light catalytically cracked gasoline and isopentane, with enough butane to set its vapour pressure and a little tetraethyl lead. Gulf counts as premium any gasoline of research octane 97 or more. Result: research octane 102.7 and motor octane 95.2 with 2.7 cc of tetraethyl lead per gallon, at 10 lb Reid vapour pressure. Source: Condrasky & Glazier, US 3,071,535 (Gulf, filed 1959), Table III. The light cracked gasoline comes from Gulf's own cracker (FCC Gasoline); the other components are matched by kind to our blueprints that make them. Not given: blending equipment, how the cuts are made, how the lead is dosed. Danger: tetraethyl lead is a deadly poison; leaded petrol is banned for road use almost everywhere. Picture drawn by Youblob.