have always wondered what the significance of the number 76 is in the name of those gas stations - Is it the years the compant was started?, the price of gas at the time? (it would be a while back!!)
Neither. The 76 brand was started in the ‘30s Unocal was founded in 1890. I don’t know if it can be verified but it’s likely that the founders’ Pennsylvanian origins had something to do with the number.
The Conoco-Philips site is no help. 76 was originally a brand name for Union Oil. Perhaps Union 76 had a patriotic ring to it. Pure speculation.
As in 1776?
Well, that does figure into the name of the Philadelphia basketball team. 
From www.76.com
“For more than 100 years, the 76 brand, with its distinctive ball icon, has been providing high-performance petroleum products and excellent customer service. The origin and heritage of the 76 brand can be traced back to the small town of Santa Paula, CA, where in 1890, Lyman Stewart co-founded the Union Oil Company of California. Today, the 76 Gasoline brand is owned by ConocoPhillips and 76 Gasoline is sold at more than 2,700 retail fuel sites in the United States.”
So, all we need now is a time machine, then we can go back to 1890, in Santa Paula, and ask Lyman Stewart how he came up with the number…
According to the company’s corporate history “Sign of the 76” published in 1976, asking Lyman Stewart wouldn’t help. The name wasn’t thought up until 1931.
There is more info about how the initial request for a trademark of 76 was turned down because the PTO thought that people would think it was a trademark for the octane rating, which you couldn’t get. California, Oregon, Washington, Idaho, Nevada, and Arizona registered it on a state level, but a Federal trademark wasn’t granted until 1950.