Now’s not the time to drive like a jack rabbit.

Quickly accelerating and stopping your car burns through a lot of gas, experts say, and with gas prices in the United State at record levels, it can also use up a lot of money.

“Jack rabbit starts are a fuel drain,” said Charlie Vogelheim, vice president of automotive development for J.D. Power and Associates. “If you apply a lot of gas right away, you waste a lot getting the vehicle up to speed quickly.”

There are a number of theories floating around for how to get the most from a full tank of gas. While many of them will add a percent or two to your mileage rate, some aren’t worth the effort. And for at least one theory, there still isn’t a consensus.

TRUE? Filling up early in the morning means you get more gas for your money.

False.

The idea behind this is that as the day goes on and temperatures warm up, the fuel expands and therefore you are able to get less in your tank, said Marie Dodds, spokeswoman for AAA Oregon/Idaho. But this isn’t the case, she said. The difference in the volume of gasoline between 50 degrees and 80 degrees is negligible, she said, and besides, there are regulations to make sure that the pump accurately measures how much gas is going into your tank, regardless of the temperature.

TRUE? Turning off your car then restarting it uses more gas than leaving it idling.

It depends.

“You definitely get zero miles to the gallon if you’re idling,” said Mike O’Connor, owner of Bend Automotive Center, so sitting idle is wasting gas. While there’s no need to turn off a car at a stoplight, if you know the car is going to idle for a while, it might be worth the wear and tear on the starter and the little bit of fuel it takes to turn the car off and then on.

For Mitch Anderson, owner of Cascade Truck and Auto Repair, that cutoff point is anything over two or three minutes.

“Anything over a couple minutes, shut the car off,” he said.

TRUE? Cruise control means better mileage.

True.

“If you can maintain a constant speed, you’re going to save fuel,” O’Connor said.

If someone is driving down the highway and then slows down, it takes energy — and that means fuel — to get back up to speed. Anytime you change momentum, it increases fuel consumption, he said.

And setting the speed slower helps, too. At faster speeds, the engine is running faster, which takes more fuel, O’Connor said.

“At 1,000 rpm, you’re going to consume less fuel than you would at 2,000 rpm,” he said. Plus, when a car is going faster, there’s more air that the car has to push against in a set period of time, which requires the engine to work harder.

TRUE? Rolling down your windows is preferable to air conditioning, which runs on gas.

Depends who you talk to.

There have been studies that show both options don’t really impact gas consumption very much, Dodds said. It takes gas to run the air conditioning, but having the windows open does create a bit of drag, she said, adding that if you do run the air conditioning, put it on the “recirculate” setting.

However, others think the impact is more significant.

“It’ll make a huge difference,” O’Connor said of air conditioning, saying it could result in up to a 15 percent change in mileage. And if windows are rolled down all the way, the back of the car can act as a parachute, he said, catching the incoming air and making the engine work harder to move the car forward.

Anderson said having the windows down shouldn’t be too big of a problem, but one good gas saver for truck drivers is to put tailgates down, since having that barrier creates a lot of drag.

TRUE? Inflating your tires saves gas.

True.

Every pound of pressure a tire is underinflated could reduce mileage by 2 percent, Dodds said.

If there is not enough air in tires, O’Connor said, there is more contact between the tires and the road, which increases friction. That increases the resistance of the car, which then requires more energy to go.

Tires shouldn’t be overinflated beyond the manufacturer’s suggested limit, however, because in addition to blowing out, they could wear down quicker.

More tips for better mileage

• Take the roof rack off your car to reduce drag and don’t drive around with extra weight in the car.

• Keep the engine well maintained, changing air filters and oil so everything runs smoothly, and check brakes.

• In a car with a manual transmission, keep the car in an appropriate gear.