Friday 17th March 1967
Star grading of petrol was introduced in the UK based on a British Standard set of octane ratings. Under this system one star was the lowest grade, 2 star was 92 octane, 3 star 95 octane 4 star 98 octane and 5 star 101 octane. The lower end was for the low tuned/low compression older design of engine, the middle range for more modern higher compression engines and five star was for large, fast and powerful engines. Most cars would run happily on three star petrol (assuming the timing was set correctly) but most motorists seemed to believe that four star was ‘better’. Most stations offered two, three, four and five star grades.