Was gas prices always 9 tenths?

Gas prices in the U.S. have not always been expressed with the "9/10 of a cent" notation. This practice began in the 1970s as a marketing strategy to make prices appear lower; for example, $3.99.9 is perceived as cheaper than $4.00. While it has become commonplace, the practice is not universal and has evolved over time with fluctuations in pricing and consumer trends.