With the statewide average price of regular gasoline passing $3.40 last week, drivers are looking for ways to cut their gas consumption. "There's lots of things you can do," said George Nitta, host of a local radio show about cars. If you really want to save gasoline, get a bicycle, Nitta said. "It goes from free all the way up." We offer a few suggestions below. They are ranked according to the percentage by which they will reduce your gas bill. Savings may vary depending on your car, driving habits and where you drive.

100%

WALK

This healthy lifestyle isn't something most people would consider feasible, especially if you live in Kapolei and work 21 miles away in downtown Honolulu. But if you can, you'll save $1,330 a year, not to mention what you'll avoid in car repair and insurance costs. This and other examples in this story are based on a Hawai'i driver who travels 9,000 miles a year in a car getting 22 miles a gallon. The driver pays $3.25 a gallon.

64%

TAKE THE BUS

You'll save $850 a year if you switch to monthly $40 bus passes on O'ahu.

41%

CARPOOL

You'll cut almost $11 a week, or about $550 a year, if you carpool and only drive two days a week to work.

31%

DRIVE SLOWLY

Avoid aggressive driving — including "jack-rabbit" accelerating, braking hard and cruising at 75 mph — and save about 31 percent. Driving 65 mph compared to 55 increases your consumption by 20 percent.

27%

DRIVE A FUEL-EFFICIENT CAR

Selling a car that averages 22 miles a gallon and getting one that averages 30 miles a gallon will save you $355 a year in fuel costs. Making a switch to a motorcycle or bicycle would provide more savings.

19%

CUT EXCESSIVE IDLING

Here's a shocker: you get 0 miles a gallon when you sit in an idling car. Shut it down if you expect to idle more than a minute. You could save as much as 19 percent by turning off the car while waiting for someone in a parking lot or walking into a fast-food restaurant instead of using a drive through. They don't recommend shutting down while you are waiting for a green light, though.

14%

TELECOMMUTE

You save $182 a year if you telecommute, i.e. work from home, once a week.

10%

CHANGE AIR FILTER

You get as much as 10 percent poorer mileage if you have a gummed-up air filter. Nitta and others recommend people switch to K & N air filters, which cost a little more but can be cleaned and reused. Consumer Reports said dirty air filters don't have as great an impact on gasoline mileage in newer cars because they've got computers to adjust the air-fuel ratio if there's less oxygen coming through the filter.

7%

COVER THAT TRUCK BED

A study by Western New England College engineering students found that pickup truck fuel consumption can be reduced by adding a soft tonneau cover over the bed.

5%

USE GASOLINE CREDIT CARDS

You can get up to a 5 percent savings on gasoline by using credit cards that grant discounts or rebates. Aloha's charge card gives a 2 cents per gallon rebate, while AAA's Visa credit card gives up to a 5 percent rebate on fuel purchases. Caveat: Your potential savings evaporate if you don't pay off the entire monthly balance and incur finance fees.

5%

GET RID OF THAT ROOF RACK

Removing a fully loaded rack from your roof can save you 5 percent through reduced aerodynamic resistance. Consumer Reports attached a Thule Cascade 1700 cargo carrier to a Toyota Camry and found it sliced 6 miles a gallon from the mileage. Results differ for various models and cars.

4%

TUNE UP YOUR ENGINE

The benefit can vary, depending on how badly your car needs an engine tune up. A bad oxygen sensor can dramatically cut into mileage by as much as 40 percent.

3%

USE LOWER-GRADE FUEL

Read your car manual. If it says a higher grade is "recommended," you can experiment and see if your car runs well on a lower grade. This typically will save 10 cents a gallon. If the manual says a certain grade is "required," don't experiment.

3%

CHECK TIRE PRESSURE

There's debate about whether this provides substantial gas savings, though the U.S. Department of Energy's site says you can save up to 3 percent with proper inflation and wheel alignment. But there are other reasons why you should do this, including better handling and longer tread life. If you have a choice between buying wider or narrower tires and are worried about fuel mileage, get the narrower ones.

1-2%

TRUNK JUNK

Taking out 100 pounds of extraneous items in your car will save you up to 2 percent in fuel.

1-2%

CORRECT OIL

Using a different grade of oil than the manufacturer recommends can lower your mileage. Nitta recommends using Royal Purple synthetic oil. Savings can total as much as $26 a year.

NO DIFFERENCE

AC ON THE FREEWAY

There's no question that running the air conditioning in town traffic will eat more gas. But the mileage differences between rolling up the windows and using your air conditioning on the highway versus opening windows and no air conditioning is negligible, according to a test by Edmunds.com, an automotive information Web site.

Sources: U.S. Department of Energy Web site, www.fueleconomy.com and Edmunds.com.

Reach Greg Wiles at gwiles@honoluluadvertiser.com.