Gas Prices

I read in the Economist that San Francisco, CA (or maybe it was the Bay Area, CA or even CA in general) has the dubious distinction of having the most expensive gas in the U.S. Fortunately, I don't drive a Mack Daddy SUV or other gas-guzzling vehicle. In fact, my little New Beetle is the most fuel efficient, snazzy looking, compact vehicle around... except for the New Beetle Convertible which I sadly cannot possibly justify. Even so, I'm always on the lookout for cheap gas, and was therefore quite thrilled to find that GasPriceWatch has a feature which shows gas stations with the lowest prices in any given area in the U.S. or Canada.

Now I've always been told that gas is a commodity, and so all gas with a specific rating, e.g., "87" (I'm not even sure what that means), is the same. It's been a while since I looked at the oil & gas industry, but I assume that the uniformity is due to the fact that there are only a handful of producers sourcing this stuff. Given my assumptions, which may be incorrect, I wonder about this little independent gas station (I'll call it Station X) I pass by on the way to work which has significantly cheaper gas (by about $0.20/gallon) than most other gas stations in the vicinity. How do they do it?

In an effort to save money, last week, I filled up my tank with Station X's 87 gas (at $2.10/gallon). Now my BugMobile usually goes ~350 miles before I hit the red line and have to fill it up. This time, however, I had only driven ~300 miles before this occurred. That's 50 miles less! I'm a suspicious person by nature, so the thought crossed my mind whether Station X adds funky stuff in their fuel to "bulk it up". So I've decided to run a crude experiment. I filled up with Station X's gas again this morning and I'm going to see how far I can go before I need to refuel. Then I'm going to switch to another gas station's gas, and compare the mileage. I'll keep you posted on my findings.