Why does the price per gallon of gasoline always end with nine-tenths of a cent?

Because they don't want to add another cent , to make you think you are getting it cheaper. I mean come one what if you only want to buy 9/10 Th's of a gallon. ...lol

well, my father is in his 50's and he told me about when he was in his 20's or so that the gas wars between different companies were actually battling with tenths of pennies per gallon of gas. And people actually bought it! eventually the penny wars needed to end and i forget who/how but all the compannies decided to keep the 9/10 of a penny on the chart. and just go back to full pennies being changed. It was also a factor that you could fill your tank back then for $2.00 and now adays it cost $30.00 on avarage. You can now see how to us in this genaration, a tenth of a penny doesn't seem so much. However back then it was the difference in $2.00 or $2.10! and back then $.10 was able to actually buy stuff!

Because if they made it any higher, it would not sound as inexpensive as ending with nine-tenths of a cent. In other words, they want their gas to sound like it's cheaper so that you will give them business instead of going elsewhere.

The same reason stuff in the store is priced at $9.99 not $10.00.

The seller can get he most possible for the item, and the psychology of the little number makes it seem a lot more less than the next higher number.

Good question. I've always wondered that but never thought of asking here.

I guess it's important if the price is cheap, but at the current price, it should be irrelevant.