Posted by Elisabeth Leamy, Fri Jun 29 2007, 09:09PM

CARS: Gasoline

CARS: Gasoline
Getting out of town for the 4th of July? Most Americans say they won't let high gas prices change their plans. So instead of changing your plans, change your ways!
AAA says only 5% of the cars sold in the United States require premium gasoline. But premium accounts for 20% 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, $208 per year!

Using a higher-octane gas than the manufacturer recommends offers no benefit at all. 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 is not 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 mid-grade.

Most gas stations offer regular (usually 87 octane), mid-grade (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."

There are other ways to save money on gas too. Here's a novel idea! Try driving the speed limit. AAA says driving 65 miles per hour instead of 55 improves your fuel consumption by 20%. The auto club says going 75 mph instead of 65 gets you another 25%! 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 website. Finally, the day of the week could determine whether it's your lucky day. Somebody with nothing better to do charted gas prices. They discovered prices at the pump tend to creep higher toward the end of the week when more people are traveling. Prices start coming down on 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 to 25%. 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.


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