Why are the prices on gas pumps always in fractions?

Matthew:

What's going on with the prices shown on gas pumps? They're always in fractions-- $1.29 9/10.

-- No Name, faxland

For this we'll have to fuel up the time machine and motor back, back, back at least 65 years, to the introduction of the automatic gas pump. The first models permitted prices to end in some odd tenth of a cent, just as they do today. In the early 30s, a penny was worth something, and so was a tenth of a penny. So if a station owner could set his pump price at 19.7 cents a gallon, he'd do more business than the station that charged 19.8 cents. Besides, wholesale gas prices rise and fall by tenths of a cent, so it's an industry standard. Federal price controls on gas in the 70s dictated profits at the pump, and it was common then to see prices that ended in 3/10 or 7/10 or whatever, depending on the results of that day's cost-plus-profit formula.

But now we have no price controls, and the penny is merely a quaint annoyance, valued only by children too young to say, "Hey, cheapskate, give me a dollar." So why do we still have the tenths on gas pumps? It's partly tradition, partly the Ginsu Knife effect. Ever notice that whatever cheesy product is being touted in those TV commercials, the price is $19.95? Never $20. We'd laugh in their faces if they asked us to pay $20. But $19.95, well, that's still down in the teens. That's not so bad. We can afford that. Gas is $1.29.9 a gallon-- hey, that's a whole lot cheaper than gas that's $1.30 a gallon. And some of today's pumps actually have the 9/10 printed permanently on the metal next to the adjustable dollar and cents figures. The pump couldn't be raised or lowered by a half cent even if the owner wanted to. It's an extra almost-penny that we have dragged with us since the beginning of petroleum time.