With the price of gasoline hovering around the $4 per gallon mark, more people are thinking about affordable transportation which is more efficient on fuel. It's a basic rule of economics. There isn't more supply to bring the prices down, so consumers find a way of conserving and cutting costs, thereby reducing demand for gasoline. Automobile manufacturers are beginning to respond, among them: the Ford Motor Company.

Ford has produced the 2009 ECOnetic Fiesta. It's a subcompact which seats five and gets a whopping 65 miles per hour. So why aren't Americans flocking to their dealerships to buy this fuel sipper. Simple. They can't.

The ECOnetic is only offered in Europe. Why? Because this car doesn't burn gasoline. It's powered by diesel, a fuel choice generally not favored by Americans, even though technology breakthroughs have made diesel automobiles a cleaner, more powerful mode of transportation.

Diesel automobiles have actually become the cars of choice in Europe, where gasoline prices range from $6 to $12 per gallon. Volkswagon and Mercedes-Benz have been producing so-called clean-burning diesel cars for years. According to Business Week, only three percent of the cars on the road in the U.S. use diesel fuel, mainly because diesel costs 40 cents to a dollar a gallon more than gasoline due to taxes aimed at commercial truck fleets.

If Americans truly want automobiles which burn cleaner and get more miles-per-gallon, they will have to vote with their pocketbooks. The technology doesn't yet exist to have efficient electric or hydrogen-powered cars. The infrastructure doesn't exist to easily refuel natural gas burning cars. Diesel is widely available now. Hybrids are an option, but they still burn gasoline. If more Americans purchased diesel powered cars and lobbied their senators and congressmen to reduce the obscene taxes on diesel fuel, we too could have access to automobiles which are easy to refuel and get very high fuel economy.

Today, I am launching a new, multi-part series called "Where to find the Cheapest..." Each part of the series will focus on a new item, which people are trying to find for the lowest price possible. With the price of gasoline at an all-time high, I figured "Where to Find the Cheapest Gas" is as good a place to start as any.

About five years ago, when I first moved to Oklahoma, I enjoyed some of the cheapest gas prices in the country. At the time, gas was about $1.23 a gallon. I didn't know it then, but those were good times. I could fill my car's gas tank for about $14. Not bad! Now, $14 barely gets me a quarter tank of gas in my mini-van, and that certainly doesn' t last very long.

We all know the tried-and-true advice of making sure you have enough air in your tires, keep your car tuned up, get your oil changed every 3,000, etc. This is not one of those articles. This article is about finding the rock-bottom cheapest gas possible...although these days, cheap gas is relative. In Oklahoma, I'm paying about $3.10 a gallon. In some areas of California, gasoline is more than $4 a gallong. Yikes.

Oddly enough, gasoline prices can vary wides from one gas station to the next in your very own city. Near my home, gas is always more expensive, because it is a nice suburb next to Oklahoma City. If I drive about 10 miles down the road, closer to Oklahoma City, gas prices drop nearly five cents a gallon, just because it's in a different zip code. I usually go there to get my gas because I have to drive there every day anyway. I probably wouldn't travel that far just to get gas, that would defeat the purpose of going there in the first place.

If you aren't sure where the cheap gas in your city is located, check out Gas Buddy.com. Users report cheap gas prices to Gas Buddy, and they are posted for everyone to see. You can even search by zip code to locate the cheapest gas prices.

If the gas in your area is about the same no matter where you go, try to make those gasoline purchases work for you. If you have a child that you hope to send off to college one day, sign up for Upromise. If you register your credit cards at Upromise, a percentage of your qualifying purchases are socked away in a college fund for your kid. You can even roll over those savings into a 529 college savings plan. One of those "qualifying purchases" is gasoline at ExxonMobil stations. Every time you buy gas and use your credit card, a few cents out of every gallon is being saved toward your young one's college fund. In the interest of full disclosure, Upromise is an advertiser at Savvy Frugality, but I am also a user. In the past few years, about $75 has been placed into my kids' college fund as the result of purchases I would have made anyway. Now, $75 won't exactly pay the tuition, but it's free money.

So-called "gas cards" have been around for awhile, but now you can get gas credit cards with rewards. If you are in the habit of paying off your balances every month, this might be a viable option for you to purchase gas with your card, pay it off, plus earn rebates on your gasoline purchases. The BP Visa Rewards Card offers a five percent rebate on purchases after an introductory period, but here are others as well.

Of course, some gas stations will cut you a break on the price of gas if you leave the credit card at home. There is a gas station on Route 66, not far from where I live, that doesn't even accept credit cards. All transactions are in cash, but the price of gas there is usually about five cents a gallon cheaper than other it is at other nearby gas stations. Find those stations in your area, and bring your cash. It can save you a few bucks over the course of a few fill-ups.

Aside from these ideas, I have simply started driving less. I only live a few blocks from my job, so I have started walking more. I'm having some maintenance done on my bicycle, and I plan to use that more, too. If you have a decent public transportation system in your area, invest in a monthly bus or subway pass. It will certainly cost less than filling up your car's tank a couple of times a week.

With oil prices recently hitting $100 a barrel, and gasoline expected to average $4 a gallon for regular unleaded, driving a car is about to become a lot more expensive. As I filled the tank of my mini-van last night, and paid $53 for the privilege, I fondly thought back to the days when I didn't even own a car.

I'm not talking about my high school days, although I didn't own a car then, either. In fact, I didn't own my first car until I was 23 years old, and I was just fine without one. I had lived in Norfolk, Virginia, which has a great public transit system. Back then, a five mile trip on the bus from the Navy base to Military Circle Mall was 50 cents. If the place I needed to go to was within a mile or two, I walked. I walked a lot, and I was in great shape back then, too.

I lived in New York for awhile as well, and there are literally millions of people in the city who don't own cars. They either take a train, a bus, a taxi or they walk to get to where they need to go. It wasn't until I moved to Minneapolis that I needed to buy a car. They have buses there, too...but I needed a car for my job and to drive home on the weekends, which was 120 miles from Minneapolis. For the most part, in a major city, you probably can get by without a car.

Our cars represent a bit of independence, a "home away from home" and many people are reluctant to think about not having a car, or using theirs less. But, that's exactly what I have decided to do. I do need my mini-van so my wife can get to doctor appointments and for work-related activities, but we will be using it a lot less. After I spent $53 buying gas last night, I informed my wife we would be grouping our errands for the week into one day. Grocery shopping, doctor appointments, errands around town...they all need to be scheduled on the same day as much as possible, to cut down on individual trips all over town.

In about two weeks, I will move to a new home which is located about half a mile from my job. I will be walking to work most of the time, and riding my bike in the summer. The gas in the van can be used for errands and to take my son to school, which is located about 10 miles from where we will live.

In Oklahoma City, where I live, there are other options to driving as well. The city's transit system has a bus pass which allows people to ride the buses an unlimited number of times for $40 per month. That's less than what I paid for a tank of gas. I'm going to get one of these for my son, so he can take the bus from school to his job. It will save me plenty of money in the long run. A tank of gas currently lasts me about five days. Since a tank of gas costs about $50, well...you can do the math. I'd rather not continue to pay $300 a month for gasoline.

With gas prices on the rise, now is the time to develop alternative transportation plans. If you can't give up your car altogether through public transit, carpooling, walking or bicycling, you can at least use some or all of these methods to CUT BACK on your reliance on your car. It's not as convenient, but it will save money...and you might even get into shape while you're at it.