How to Save on Gas July Fourth

July 3, 2007 — -- Getting out of town for the Fourth of July? Most Americans say they won't let high gas prices change their plans. So instead of changing plans, change your ways.

AAA says only 5 percent of the cars sold in the United States require premium gasoline, but premium accounts for 20 percent of all gasoline sold. What a waste. Say you use 20 gallons of gas per week. Regular costs an average of 20 cents less per gallon, so you'll save $4 per week or $208 per year.

Using a higher octane gas than the manufacturer recommends offers no benefit, but some people remain convinced that premium gas will make their cars go faster or get better mileage. It's just not true.

All the term "octane" refers to is a fuel's ability to help your car resist engine "knock." This knocking, rattling or pinging sound comes from premature ignition of fuel in your engine. Light knocking isn't harmful to your car, but heavy, persistent knocking can cause engine damage.

Your car is built to run on whatever grade of gasoline is recommended in your owner's manual. The vast majority of cars are designed to run on regular octane. If the manual says premium is "required," use it, but if it's just "recommended," ask your mechanic about using midgrade.

Most gas stations offer regular (usually 87 octane), midgrade (usually 89 octane) and premium (usually 92 or 93). These levels vary from state to state. For example, one state may require all premium gasoline to have an octane of 92 or above while another state may allow 90 octane to be labeled premium. When you read your owner's manual, be sure to note the precise octane level your car requires. Then look for that level rather than relying on a generic term like "regular" or "premium."

Slow Down!

There are other ways to save money on gas. Here's a novel idea: try driving the speed limit.

Driving 55 mph instead of 65 improves your fuel consumption by 20 percent, AAA says. Erratic acceleration and braking burn fuel too up to 50 cents a gallon.

Keeping your car tuned up is another way to economize. And properly inflated tires save you money, too. They cause less road resistance. You can also take heavy items out of your trunk to lighten the load.

Now here are a couple more novel ideas. Some gas stations still offer discounts if you pay with their credit card. If you're taking a trip, keep in mind that some hotels and theme parks provide gas vouchers to encourage people to visit. You can inquire when you check in or go to the Web site.

Finally, the day of the week could determine whether it's your lucky day. Somebody who charted gas prices discovered they tend to creep higher toward the end of the week when more people are traveling. Prices start coming down Sunday and supposedly the best day to buy is Wednesday.

Now a caution: When gas prices go up, so does hype about "gas-saving" products. The Federal Trade Commission warns that very few devices, oils or additives actually improve gas mileage. The ones that do work provide very small savings. The manufacturers claim these products will save you 12 percent to 25 percent. But the Environmental Protection Agency conducted several tests and found the claims are false. In fact, some of these products can even damage your engine.

To be a SAVVY CONSUMER …

Do your homework:

Read your owner's manual and use the level of octane recommended. Know what level of octane constitutes "regular" or "premium" in your state. Slow down and accelerate and brake gradually. Keep your car well tuned, your tires properly inflated and your trunk empty. Try a gas station credit card that offers a discount and ask about gas vouchers. Note whether gas prices in your area fluctuate depending on the day of the week. Be skeptical of "gas-saving" products. Go to www.ftc.gov for more information.