Gas prices haven't been this low since 2007

US drivers can hail the return of the gold old days, if they consider 2007 to be "old." That's the last time gasoline and diesel prices were as low as they are today, according to the Diesel Driver. And some experts are saying gas prices could fall further on an oil-inventory glut and a continued decrease in demand from China.

Truckers, in particular, can celebrate, since diesel fuel is priced on average at about $2.48 a gallon right now, about 48 percent less than a year ago. Regular gas costs about $2.06 a gallon, on average, or about 35 percent less than it did last year. If you're looking to see how the trend is going, both gas and diesel prices are down two or three cents a gallon in the past week alone.

These costs are driven largely by the Midwest. Michigan has the country's lowest-priced gas at about $1.80 a gallon, and states such as Oklahoma, Missouri, South Carolina and Ohio are all within a penny or two of that figure. Not as happy are the folks out west. Hawaii, per usual, has the country's most expensive gas at more than $2.80 a gallon, followed up by California at $2.69 a gallon and Nevada at $2.53 a gallon.

The only folks who may not be ready for the full-fledged party are sellers of hybrid and plug-in vehicles, which have been banking on higher gas prices to push consumers towards alternative powertrains. Last month, US sales of hybrids, plug-ins and diesel fell 27 percent from a year earlier. Even after factoring out the stop-sale of Volkswagen diesels, green-car sales still fell 16 percent compared to November 2015. Who's happy now?