How to Really Find Cheap Gas

With gas prices rising, cheap fuel is all the more important. To find it, start with the price per gallon. There are plenty of websites that offer this information, but simply keeping your eyes peeled can work well--a lot of websites rely on user input to get their prices and they aren't always complete or up to date. You may find lower prices by being observant.

Having the price per gallon leaves open the question how large a gallon you're getting. Officially, a gallon is 231 cubic inches. But it would seem that not all gas stations calibrate their pumps to deliver the same size "gallon." If you watch your mileage closely and buy gas at several stations posting cheap prices, you may learn that some stations routinely pump more "gallons" into your tank than others. This means they are selling a smaller "gallon." Obviously, you want to buy the largest "gallon" you can.

To figure out which stations sell smaller gallons and which sell larger ones, keep track of your mileage between fill-ups. Using the trip odometer on your car may be the easiest way of doing this. Keep track of how many gallons go into your tank with each fill-up and calculate the mileage. Ideally, for the sake of consistency, you should use the same pump at each station you buy from and never overfill the tank. Buy at several cheap stations and then compare your mileage calculations. If one station stands out as giving you lower mileage (by selling you more gallons per fill-up), it may use a small "gallon." Conversely, if a particular station stands out in giving you good mileage (by selling fewer gallons per fill-up), it may use a larger "gallon."

I've noticed that there can be apparent differences of perhaps as much as 10% or more in the size of the "gallons" sold by different stations. With gas prices levitating above $3 per gallon, a "gallon" that's 10% smaller than a true gallon is actually more expensive if its posted price is as much as $0.30 lower than a station selling a true gallon. Since a price break of 30 cents per gallon will capture the attention of almost any reasonably sentient driver, the size of the gallon at a particular station really does matter.

If you have the same experience (i.e., either large or small gallons) several times at a particular station, you will have probably discovered a chiseler, or, alternatively, an honest station operator. Then, you'll know where to buy gas, and where not to.

Unconventional Gas Saving Tips

You already know that, to improve your gas mileage, you should drive gently, keep your tires inflated and drive at highway speeds closer to 60 than 80. Here are a few tips that you may not have heard before. They may not work for everyone. But based on my experience, they could help you reduce your gas expenses.

Hold onto your car longer. A Ford Explorer I once owned got its best mileage after 70,000 miles. The mileage at 70K was about 10-12% better than when the Explorer was new, and about 5% better than when it had 30,000 to 40,000 miles. In fact, I got 21 mpg on the highway after the 70K mark, which was higher than the EPA estimate of 20 mpg highway mileage. Why? I think it was because the engine, transmission, ball bearings and other parts were well broken-in after 70,000 miles. A broken-in car runs with less friction, and therefore should provide better mileage. If you’re the type to trade in a new car after two or three years, think again. You may be missing out on some of the best years of the car’s life.

Try mid-grade. Once I found a gas station with a marketing gimmick of selling regular and mid-grade gas for the same low price (the level at which neighboring stations sold regular). I couldn’t pass up a bargain and filled up with mid-grade, even though my car is designed to run on regular. My mileage was about 10% better with mid-grade. I don’t know exactly why this happened. But I’d guess that because mid-grade has higher octane, it delivers a little more energy per gallon and therefore moves the car a little more efficiently. If you can find mid-grade for a price only a few cents higher than regular, you might try filling with mid-grade just to see how things go. (For those budget-minded drivers who are wondering where they can find the station that sells mid-grade for the same price as regular, I don’t have its name or exact address, but it’s in Burnsville, MN on or near Nicollet Ave.)

Avoid ethanol. Although this notion is heretical in farm states, try using gas that doesn’t contain ethanol. Ethanol reduces mileage slightly. The times I’ve used regular without ethanol, I seem to get about a 5% improvement in mileage. If you can find plain old regular for more or less the same price as regular with ethanol, give it a try and see what happens.

Clean up your car. If you clean up your car, you’ll almost surely lighten it. Weight is a critical factor in mileage. There could easily be 50 or 100 pounds of excess weight in your car (you know, the golf clubs you haven't used in months, the old home furnishings you still haven't donated to charity, etc.). Lighten your car and see an uptick in mileage.

Don’t idle the engine. Modern cars have fuel injection systems that use very little fuel to start the engine after it’s warmed up (which would be after the first half-mile or mile following a cold start). That’s why hybrid engines save on gas. In a hybrid, the gas engine shuts down when the car is traveling at low speed or is stopped, and then starts up when more power is needed. Sometimes, European drivers turn off their engines at long stop lights. America’s go-go culture might make that inadvisable here. But, otherwise, if you’re likely to wait more than about 30 seconds, turn off the engine.