Consider parking at a store in the double parking slots. This works only when both slots are available. Enter as you normally would into the chosen space, but continue on to the other side so the front of the car is facing the parking lane.

This eliminates two times of accelerating (once to back up, and once to start up again forward), by simply being able to pull out forward.

Sure, you might have to park farther out, but I usually do that anyway to avoid unwanted door dings, and I get a little more physical activity in my day. Hope this helps!
posted by cemnei on November 13 2008

this tip works for 89% of voting Fuelly members.

Before I start my cars engines, I make sure I am ready to drive. I adjust the seat if necessary, make sure any items I have with me are secure, fasten my seat belt, adjust the mirror, adjust the tilt steering, put on my sun glasses if necessary and do anything else that needs doing. It may only take 20 or 30 seconds to do these things but it you start the engine first, that means 20 or 30 seconds of letting the engine wastefully idle.
posted by spacetime on November 09 2008

this tip works for 91% of voting Fuelly members.

This works well on manual transmissions. When you know you'll be slowing, i.e. you can see the light well ahead turn yellow, just take your foot off the gas, shift into neutral and gently coast on until you need to stop. There's no sense speeding to a stop light and wasting perfectly good momentum in the process. Odds are the light may even turn green again by the time you get to it.

Similarly, when cresting a hill, so long as the road ahead is safely clear, let gravity do the work instead of your engine. When slowing while going up a hill, again, let gravity do the work.
posted by Jabber on September 19 2008

this tip works for 84% of voting Fuelly members.

Generally speaking, holidays (especially 3 or 4-day weekends) mean a higher than usual demand at the pump. Higher demand = higher prices. So don't wait until the holiday and fill up a day or two before.
posted by joeperez4 on September 14 2008

this tip works for 93% of voting Fuelly members.

If you can remove your roof rack, do so if you're not going to be using it, even for a week. The extra wind resistance reduces your MPG.
posted by bruzie on August 27 2008

this tip works for 84% of voting Fuelly members.

If you are replacing your tires anytime soon you should look for tires that are designated as Low Rolling Resistance (LRR). LRR can help improve your fuel economy by 2-4%. Be advised though, LRR tires may be hard to find. Look for Michelin MXV4+ or Goodyear Viva2.
posted by modysy on August 25 2008

this tip works for 85% of voting Fuelly members.

Sites like gasbuddy.com depend on their users to submit current gas prices to the main site for everyone to see. It's a good idea to compare prices before ever having to leave your house.
posted by Nettle on August 24 2008

this tip works for 73% of voting Fuelly members.

You can safely inflate your tires, in most cases, to a higher pressure. For example, my minivan manual says to inflate to 35psi, but the max pressure on the tire sidewall is 44 psi. I find I can run at 40psi without making the ride too harsh, and I've picked up a couple of MPG. Your mileage (and comfort level) may vary. Never exceed the cold inflation pressure embossed on your tire sidewall.
posted by b3n on August 23 2008

this tip works for 67% of voting Fuelly members.

Modern lubricants flow well in cold weather, and do their job better than their previous formulas. Modern engines are also made to much tighter tolerances. Fuel injection has eliminated the choke and the need for a warm manifold.

You'll get better mileage if you only warm up the car for 30 seconds or so. The car will warm up faster with gentle driving for 5-10 minutes than it would idling for the same amount of time. Gentle driving will also warm up your brakes, preventing warped rotors, etc. that can be caused by an abrupt stop with cold brakes.
posted by chuckbalog on August 17 2008

this tip works for 95% of voting Fuelly members.

As the television show Mythbusters has proven—when traveling under 50 MPH it is more fuel-efficient to leave your windows down and your AC off. When traveling over 50 MPH it is more fuel-efficient to have your AC on and your Windows up.
posted by TikiTantrum on August 10 2008

this tip works for 85% of voting Fuelly members.

Look ahead, if you see a light is red just coast. You're not getting through the intersection until the light turns green anyway so why rush?

You save the gas you didn't use to speed the car up to charge the red light, AND improve the chance that the light will turn green while you're still rolling. If you're still rolling when traffic moves you've saved the gas you would have used to get to that speed too!

Also, less accelerating and braking will make for a more comfortable ride for your passengers.
posted by hudson on August 09 2008

this tip works for 99% of voting Fuelly members.

Pretend you have a cup of hot coffee on the dashboard. Accelerate and decelerate in a manner that would not make the cup of coffee spill. That is the way you can improve your MPGs.
posted by pvertes on August 09 2008

this tip works for 89% of voting Fuelly members.

If it's a nice day outside, roll the windows down a little. Your A/C compressor eats away at your gas. In Texas, I noticed 7 mpg difference between the summer months and the spring/fall months as I was not using my AC during the fall or spring.
posted by JC on August 09 2008

this tip works for 83% of voting Fuelly members.

Despite common belief speed is not really connected to MPG. The Revolutions Per Minute (RPM) of your car's engine is what really matters.

If your car has a Tachometer watch your RPM's, keeping them low will use less fuel. Depending on the gearing of your transmission is what determines how fast you travel at a certain RPM.
posted by TikiTantrum on August 08 2008

this tip works for 82% of voting Fuelly members.

Though some people will tell you never to accelerate quickly, sometimes it's better to have a bit of a lead foot. Seriously. There are two main reasons for this.

First: your engine likely operates at a higher efficiency (i.e. burns more fuel that would otherwise be wasted by your catalytic converter and just go out your exhaust) at around 80% acceleration.

Second: Your car gets better MPG at higher speeds up to about 55-65 mph depending on your car. So as long as there aren't too many red lights ahead of you, it's best to get your car to the maximum legal speed as soon as possible.
posted by jjmatt33 on August 08 2008

this tip works for 45% of voting Fuelly members.

Go inside rather than use the drivethrough. If you idle for more than 10 seconds, you're using more gas than needed for restarting your car.
posted by bonehead on August 08 2008

this tip works for 94% of voting Fuelly members.

Keep your tires inflated to the proper pressure. Low tires mean more surface area, and therefore more friction, which translates to higher fuel consumption. Check your tire pressure while your car is refueling. If you need more air, pump up while you are there!
posted by terrapin on August 07 2008

this tip works for 97% of voting Fuelly members.

If you're going to be sitting in your car with the engine running for more than 30 seconds or so, it saves fuel (which would be zero mpg at a standstill) to turn the engine off. Hybrids are famous for this, and it's a bit trickier to do in a regular car, but if you're at a long light, or waiting in a long line of cars, it does decrease fuel usage to simply turn off your car's engine.
posted by mathowie on August 01 2008

this tip works for 88% of voting Fuelly members.

On steady flat roads (especially at higher speeds), cruise control can save a lot of fuel by limiting accelerations and generally resulting in a smoother, more efficient trip.
posted by mathowie on July 31 2008

this tip works for 87% of voting Fuelly members.

When driving in stop and go traffic, try to keep a couple car-lengths of distance in front of you to minimize the chances of having to come to a complete stop (which requires you to start again, using more fuel). By maintaining some distance and a steady very slow speed, you can carry your momentum through traffic and save fuel.
posted by mathowie on July 31 2008

this tip works for 98% of voting Fuelly members.

It's obvious of course, but a great way to save fuel on all the short errand trips you do from home is to either walk, ride a bike, or at the very least cluster your errands into fewer trips. Riding/walking will also keep you healthy as well as save money and fuel.
posted by mathowie on July 31 2008

this tip works for 87% of voting Fuelly members.

Changing your oil filter and air filters as recommended is a good way to keep your engine running more efficiently and saving more fuel. Oil changes are common but you might forget to change the air filter often enough. Try it and you may see an increase in power and gas mileage if it's been a while.
posted by mathowie on July 31 2008

this tip works for 97% of voting Fuelly members.

Punching the gas from a stop (aka "jackrabbit starts") is a great way to waste fuel. You can optimize gas by starting from a stop slowly and gradually. Generally, drive as if you are taking a baby home from the hospital -- smooth, slow, and careful, to save the most fuel possible.
posted by mathowie on July 31 2008

this tip works for 92% of voting Fuelly members.

As much as I love to drive fast, it's a fact that you're on the freeway and you are driving beyond 65mph, your fuel economy will go down. As much as I like getting home faster by driving 80mph, going 55mph saves several mpg.
posted by mathowie on July 31 2008

this tip works for 93% of voting Fuelly members.

Don't leave heavy items you don't need in your car's trunk or truck bed. Put away tools, golf clubs, skis, whatever and watch your mileage go up. I noticed my car lost 2-3mpg when fully loaded on a long car trip, and returned to normal when emptied.
posted by mathowie on July 31 2008

this tip works for 98% of voting Fuelly members.

You can improve your gas mileage by around 3.3 percent by keeping your tires inflated to the proper pressure. Under-inflated tires can lower gas mileage by 0.4 percent for every 1 psi drop in pressure of all four tires. Properly inflated tires are safer and last longer. (from fueleconomy.gov.)
posted by pb on July 25 2008

this tip works for 98% of voting Fuelly members.