We've all become a lot more interested in the secret science of what determines gas prices. The Cincinnati Enquirer just painstakingly analyzed price data from 716 gas stations in May and June using the Oil Price Information Service. Their most peculiar and potentially useful finding was that gas is cheapest on Tuesdays.
Over the whole period among all those stations, gas was an average three cents a gallon cheaper on Tuesdays than Wednesdays, and once it jumped 16 cents overnight. The Enquirer found that Wednesday was the day stations raised prices for the upcoming weekend, and that they lowered it just after the weekend.
The Enquirer says gas mavens have known this all along, though it was certainly news to me. If gas stations are expecting to even out their demand with pricing, will it work if people don't understand the weekly cycle? The story says: "Experts say gas always has been cheapest midweek, when demand is lowest. But the exact cheapest day is likely to change at any moment, without notice...." So, if we all start buying on Tuesdays, the cheapest day will move.