If you recently purchased a hybrid car, taken by its promises of fuel efficiency as high as 60 miles per gallon, you might have been a little disappointed if you just couldn't squeeze that much travel out of the tank.

Part of the problem may have been misleading advertising. The Environmental Protection Agency recently revised its system for estimating a vehicle's gas efficiency. The new ratings will appear on the window stickers for 2008 models.

The new numbers will attempt to more closely replicate real driving conditions, not the ideal conditions of driving through an EPA laboratory. That means they'll factor in things like our tendency to drive with a lead foot on the gas pedal, with the air conditioning cranked up as high as possible.

They'll also try to factor in things like wind resistance and road surface resistance. (Maybe they can replicate the fuel economy effects of the potholes and speed bumps in my neighborhood, too.)

The government has already released some revised numbers for older model cars. You can check the new fuel consumption estimates for your vehicle here. I was disappointed to find that my 2007 Jaguar XK convertible can only be expected to get 16 miles per gallon in the city, not the 18 miles previously advertised.

OK, so I don't drive a Jaguar. My actual car's combined city and highway driving mileage dropped only three miles per gallon. Larger reductions can be seen in the most efficient vehicles -- for example, the popular Toyota (NYSE:TM) Prius hybrid saw its EPA estimates drop from 55 mpg to 46 mpg (though Fool analyst and Prius owner Rex Moore still brags about getting 62.3 mpg for one of his tanks).

It might be worth checking these revised estimates and comparing them to your reality. The amount of distance you can squeeze out of a gallon of gasoline will have a lot to do with your driving habits, especially the time spent in city traffic compared with highway driving.

If your gas consumption seems unreasonably high, or gasoline's taking a big bite out of your wallet, you might want to examine your car or your driving habits. Even if the age-old advice to stop driving and take the bus isn't realistic, you can try some of these other ideas:

  • Use the lowest octane gas you can. Unless you do drive a Jaguar or some other high-performance vehicle, your car probably doesn't need ultra, premium, gold-plated gasoline. The plain, cheap stuff probably works just fine.
  • Combine as many errands as possible into a single trip. The EPA says several short trips started with a cold engine can burn twice as much fuel as a longer trip covering the same distance when the engine is warm. You'll save on gas, not to mention time and maybe a little bit of sanity.
  • Adjust your commute time to cut delays. In many parts of the country, it can be impossible to predict how long it will take to get to work from day to day. But, if you know that leaving 15 minutes early saves you 30 minutes of idling in traffic, you're cutting your gas bill without changing much at all. You'll also get to work in time to gulp down a second cup of coffee.
  • Carpool. It's often not realistic to try to carpool every day, given our unpredictable work schedules and after-work commitments. Try, instead, to carpool one day a week. Pick a day that's usually routine, like a Friday. You'll trim something off your gas costs even if you don't carpool all the time.
  • Back off the accelerator, speed racer. You'll go through a lot more gas if you're jumping as fast as possible from one red light to the next or trying to outgun everyone else on the highway. As a rule of thumb, the EPA says you can assume that each 5 miles per hour of speed over 60 miles per hour costs an extra $0.20 for gas.
  • Check the pressure in your tires and the condition of your air filter. Yes, I know you think that the technician at the oil and lube joint just wants to get more of your money by pulling out your air filter at every visit, but it does occasionally need to be changed. In fact, getting rid of your clogged air filter can improve gas mileage as much as 10%.

While you're at it, clean all the heavy junk out of your trunk. If you're carrying a lot of extra weight, you'll burn more gas.

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Fool contributor Mary Dalrymple welcomes your feedback. The Motley Fool has a disclosure policy.