Strange, but I guess you shouldn't question "why" since the price is dropping so quickly.

Like you, I saw a big difference in filling up my car's tank. I had to do a lot of driving yesterday so I topped off my tank first (it was half full). I put in only $14 worth to fill it up. A few months ago it would've taken $30 to do that.

I like to keep my tank full in the winter (to cut down on condensation in it during the cold weather) and I'm hoping the prices stay low, but I'm not gonna hold my breath for that.