The United States Department of Energy now projects that the price of gasoline will average $2.60 per gallon in 2015. That's an astonishing 23% below where 2014 looks likely to net out. If that projection bears out, then about $100 billion less will be poured into Americans' gas tanks next year. 

That $100 billion would be an incredible stimulus all by itself, but also consider the fact that you don't pay for gas only to move yourself and your family around. Embedded in the price you pay for many goods is the cost of transporting it either directly to you or to the store where you picked it up. Lower fuel prices should also reduce pricing pressure on everything that gets transported, which could help your pocketbook even more.

What's your share, and what can you do with it?
According to the Environmental Protection Agency, the typical passenger car uses around 500 gallons of gasoline per year, and the typical SUV or light-duty truck uses around 700 gallons per year. Split the difference and call it 600 gallons. If you're a one-vehicle household, then you can expect to spend about $466 less on gas next year. If you're a two-vehicle household, that works out to some $930 more in your pocket than you otherwise. That's $9 to $18 in savings each week. 

That amount won't exactly lift you from barely making ends meet into the Champagne wishes and caviar dreams of the Lifestyles of the Rich and Famous. However, it can provide some valuable breathing room in your budget. The lower price of gas gives you the opportunity to make some real headway in your personal finances without otherwise impacting your lifestyle. If gas prices hold to the Energy Department's projections, that $9 to $18 per week can be yours without your having to lift a finger.

Three priorities this windfall cash can help you with
Priority 1: If you have debt, these fuel savings give you a perfect chance to pay down what you owe more quickly. Payments above your minimum reduce the principal more quickly and thereby reduce the amount that's subject to interest compounding against you. Additionally, the faster you get your debts paid off, the sooner you're free from making that payment -- both the principal part and the interest part -- thus providing even more buffer in your cash flow.

Priority 2: If you don't have an emergency fund, this little bit of extra cash can quickly add up to be a solid foundation for one. It's generally a good idea to have at least three to six months' worth of expenses in a savings or money market deposit account in order to be able to cover the curve balls that life throws your way.

Priority 3: If you aren't adequately funding your retirement accounts, this frees up more cash to put toward your long-term future. With enough time and consistent investing in your retirement plans, becoming a millionaire is much easier than you may have ever believed. As a potential bonus, between the money you put away, the potential tax savings on money invested in a plan like a 401(k), and the possibility of an employer match on that same plan, you could instantly double your money by contributing it.

Why not spend it?
Unless you're already ahead of the curve on priorities 1, 2, and 3, the extra bit of breathing room freed up by these lower gas prices presents too good an opportunity to waste by spending more elsewhere. Given that the savings will likely amount to less than $20 per week, you won't have enough extra spending cash to make a substantial improvement in your quality of life. Using the money to get yourself caught up, out of the hole, and ahead of the game, however, could meaningfully change your life for the better.

On top of that, gasoline remains a volatile commodity. Prices may well shoot back up at some point in the near future. The better you shore up your financial foundation while lower gas prices help you to, the better you'll be able to handle those higher prices the next time they come around.