With the start of increased gas prices and all the differences about gas pricing and the different types of gas available at your local gas station, here is some information to help improve the shock at the pump.  According to Consumer Reports, there are just as many things that are rumored to improve your gas mileage that just don’t work on today’s modern cars.  Some, it has proven, including preferring air conditioning over open windows and choosing tires with low rolling resistance, don’t affect your gas mileage as much as you’d think.

Here are just seven of the mpg myths busted by the folks over at Consumer Reports.

Cheap Gas Stations Give Cheap Gas

For years, there’s been a common belief among drivers that gas purchased at independent gas stations isn’t the same quality as gas purchased from name-brand gas stations.  We’ve even heard rumors in the past that say some gas stations dilute cheap gas with small amounts of water, affecting power and engine efficiency.  Both, Consumer Reports says, are not true.  In reality, all gas stations are tied by tight laws governing the storage and pumping of gasoline, while independent and no-name gas stations usually buy gasoline from the well-known oil companies anyway.  The only difference?  Cheaper gasoline sometimes omits the additives designed to clean older engines.  With today’s modern fuel-injection systems however, that shouldn’t make much difference.

Premium gives better gas mileage

Because premium gas has a higher octane rating than midgrade or regular gas, it produces a little more power when burnt.  Designed for performance cars with large, powerful engines, premium also helps minimize the risk of pre-ignition inside highly-stressed, hot engine cylinders.  On a track, the extra boost given by premium can mean a few tenths of a second difference on a lap time.  In the real world, it barely affects performance, or fuel economy.  Consumer Reports advises that premium should only really be used in your car if your owner’s manual mandates it.  In our experience, only a handful of everyday cars are tuned to run better on premium.

Open windows kill fuel economy

Windows or Air Conditioning?  It’s a common misconception that winding down windows on your car to provide ventilation creates so much extra drag that your gas mileage falls further than it would if you use the on-board air conditioning.  Not so, says Consumer Reports.  Under lab conditions, it tested a Honda Accord along a test track at 65 mph.  Using the air conditioning to keep the car cool greatly impacted gas mileage by a shocking 3mpg.  Keeping the windows open on the other hand, affected gas mileage so little that it was impossible to measure.


Low rolling resistance tires are always best

While tires specially designed to lower rolling resistance can save you a few mpg if properly inflated and maintained, Consumer Reports advises that better tire maintenance and driver habits can easily make up the difference between an energy saving tire and a regular tire.  As it points out, lower rolling resistance tires often perform less well in wet and icy conditions than regular tires, raising your risk of accidents.  The solution, it says, is to look for a good all-round tire that combines good economy, good tire life and good grip.

Warming up the engine before driving is good

If you’re of a certain age, you’ll remember the days when you had to go outside and start your car before driving it to get the engine up to temperature before you asked too much of it.  That was in the days before advanced synthetic oils, fuel injection and electronically-controlled engines, where cold-engine wear was a major issue of premature engine failure.  Nowadays, it isn’t needed, thanks to clever systems designed to get cars up to operating temperature as quickly as possible after you start it, and oils that cling to the cylinder to protect it even when the engine is cold.

Dirty air filters kills gas mileage

Much like warming up your car, dirty air filters did used to impact gas mileage, especially in older, dirtier carbureted engines.  Nowadays however, air flow sensors and computer software carefully manages the air/fuel mix in your car’s engine, ensuring maximum fuel economy is possible regardless of the quality of air.  Where it will make a difference however, is performance. If the air filter is dirty, less air can get into the engine under hard acceleration, meaning your car speeds up more slowly.

Filling up in cold temperatures gets you more gas

The theory here is sound: the colder gasoline is, the denser it is, meaning you should be able to get more gas into your gas tank when the gas and the outside temperature are cold.  Not so, says Consumer Reports. Because gas station tanks are stored underground, the difference you’ll see in the amount of gas you can pump on a hot versus cold day is negligible.

Myths busted, but you’re the number one factor

As Consumer Reports successfully proves, gas mileage isn’t affected that much by many of the tips and tricks you’ll find floating around the Internet today.  Sadly, as with many things, the gas mileage you get out of your car depends on you more than anything else.  Try to keep calm when driving, look ahead, and make sure you’re in top form before you step behind the wheel.  A calm, alert driver is always better than a late, agitated one when it comes to gas mileage.



Here are a few simple things you can do to control your car’s fuel efficiency.

1. Replace/tighten your gas cap

Every time you stop to fill your tank, check the gas cap seal for damage and make sure your gas cap is tightened when you finish.  Fuel evaporates through a loose cap or a damaged seal, reducing your gas mileage by as much as 2 percent and potentially allowing contaminants and dirt to enter the fuel system.  Escaped fuel fumes can also pollute the air, so taking the time to inspect your gas cap can not only save you money over the lifetime of your car, but it can be good for the environment.  On all newer vehicles, a leaking gas cap will cause the “Check Engine” light to stay on.  If you discover that your gas cap is indeed broken or leaking, you will want to replace it immediately.

2. Inflate/change your tires

Checking your tires during the summer are especially important, so be sure to do a visual inspection every time you stop for gas.  A bulging sidewall could mean the tire pressure is low.  Tires that are underinflated have a higher rolling resistance, which decreases your vehicle’s efficiency, causing gas mileage to drop.  By keeping your tires properly inflated, you can improve your gas mileage by as much as 3.3 percent.  To find the proper tire pressure, check your vehicle owner’s manual or the specification sticker on the door jamb.

3. Change your oil

Using energy conserving or synthetic motor oil can also improve gas mileage, saving you money at the pump.  By reducing engine friction, these oils can improve engine efficiency by 1 to 2 percent, which in turn improves gas mileage.  Be sure to use the recommended oil viscosity range for summer, which may be a bit thicker than winter. Always refer to your vehicle owner’s manual for the recommended oil type and viscosity.

4. Replace spark plugs

Your car’s spark plugs ignite fuel by means of a spark.  Misfiring spark plugs can reduce fuel efficiency by as much as 30 percent, or 75 cents per gallon.  Even worn-out spark plugs can lead to poor engine performance and lowered fuel economy.  Replacing them improves combustion and reduces emissions.


5. Replace the engine air filter

Your car’s air filter works to remove dirt, debris, and particles that might otherwise damage your engine. Replacing a clogged air filter on an older car with a carbureted engine may improve fuel economy 2 to 6 percent under normal replacement conditions, or up to 14 percent if the filter is so clogged that it significantly affects drivability.

6. Change your driving habits

A few changes to your driving habits can make a huge difference.  AutoMD.com recommends lowering your average speed, as each 5 miles you drive over 60 miles per hour is like paying an additional 24 cents per gallon and be sure to steer clear of rapid acceleration and braking, which can increase fuel burn by as much as 40 percent. Engine idling is another gas waster, so be sure never to let the engine idle for more than 30 seconds and don’t forget to remove any excess weight from your trunk.  Finally, if you can, turn off the air conditioning and only use air that comes in through your ventilator, do it for maximum efficiency; for really hot summer days, use air conditioning on the highway, but turn it off and roll down those windows for driving around the neighborhood or in city traffic.