Remember for decades the high point for the price of Gasoline was Memorial day. then the price dropped all Summer. The price climbed again starting in October.
The reason for this is that the Refineries Switch production in the Spring and fall. In the Spring the refiners switch to producing more gasoline out of each barrel of oil do to the up coming Summer Driving Season. In the fall the refiners switch to produce more home heating oil for the upcoming winter. The big switch in the Spring for the switch has to occur at the time of the last cold snap, which can be in April, which gives the refiner only two months to Memorial day (April and May). In the fall the Switch starts around labor Day (The end of the summer Driving season) but people often wait till November to buy their Winter home heating oil, thus you have almost three months to make the Switch September, October and November). Thus the fall switch does NOT have to be as fast as the Spring Switch, thus the price of Gasoline goes up more in the Spring then in the fall.
Now the above assume a "Normal" Situation. We do NOT have that at the present time, but the reasons for the above still exists and still has some affects on Gasoline prices. The problem is that we apparently have a REAL shortage of oil, which is also pushing up the price of Gasoline. This has been the big push over the last several years. The interaction of these two reasons for the price of gasoline is what is going on now. The underlying shortage still exists and continues, but we are in the traditional Summer period when price should be decline. These two movements seems to be canceling each other out at the present time. A further factor is the high price of oil has cause people to use less oil, less demand for oil, less demand for a price increase.
All told we are in the Summer doldrums of oil prices. I expect the price to stay what it is for the normal rule of thumb is it takes four weeks for the price of oil at the well head to reach your local gas station, it takes eight weeks for a price DECREASE to reach your local station (This is the Economic concept to "Price Stickiness", known by economists for about 100 years). Thus the recent drop in prices have NOT been reflected in your local prices, and given that come September the annual push for price increase will be kicking in, more than canceling the present Summer oil price doldrums.
One last comment, Another factor is the Switch among Europeans ot Diesels over the last ten years (a switch coming to America). In the winter of 2006-2007 the price of Gasoline was low in the US, while Diesel and its cousin home heating oil went up. The reason for this is that while you can emphasis production of Gasoline or Home hearing oil (Diesel is the same as home heating oil, the main difference being the tax on Diesel) when you produce one or the other, you still get some of both. In the winter of 2006-2007, Europe suffered a severe cold snap, and used a lot of Home heating oil. This released a lot of gasoline that Europe, using more and more Diesels, had to ship to the US. Now, Europe could, and did, try to produce more Home heating oil then it normally gets from a Barrel of Oil, but gasoline was still produce and was a glut on the European market. That Gasoline was shipped to the US, and kept US gasoline prices down in the early part of 2007. Then as the summer driving season approached, gasoline prices rose and continue to raise even in the Fall 2007 period and continued till recently. This both reflected the lo price Gasoline was compared to home heating oil in the winter of 2006-2007 and a growing shortage of oil. Europe did not have a bad winter last winter 2007-2008, and the US winter came in late (i.e. in January and February NOT November and December). This forced US refiners to keep Home heating oil in production long after it was normal for them to switch to gasoline. This combination of mild winter in Europe and a late Winter in the US lead to the present prices.
Gasoline supplies seems to have caught up with demand (more to a drop in usage do to the high price then anything else). That will continue till this fall, when the demand for Home heating oil will come into play. What will be the price for Home Heating oil #2 and its duplicate Diesel #2? What will happen to it lighter cousin Kerosenes #1 and its duplicate cousin Jet Fuel (There are technical difference between these two, but there are more technical then real)? Kerosenes generally more expensive then Diesel for it is a lighter oil, but both can be and are used in the same Vehicles (Kerosenes is a better winter fuel, less likely to freeze up then diesel, through neither are in the same class as a winter fuel as Gasoline).
This occurred last year and here are the Comments made at that time on DU:
http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=266x2398