5 Gas Myths Busted

To help you increase your gas mileage and save money, we’re debunking the following 5 gas myths.

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Gas prices are expected to rise (and, in fact, are already rising) in 2011, maybe even topping $5 per gallon. Unless you drive a green car Olympian, this spike will likely affect your finances. So to help you increase your gas mileage and save money, we’re debunking the following 5 gas myths.

Gas myth #1: Premium is better

According to the Federal Trade Commission, high-octane fuel won’t give your car better gas mileage, increase its performance, or make it run any cleaner. In general, regular octane works just fine for most cars. If your owner’s manual recommends pumping regular, there’s no need to upgrade to premium.

Gas myth #2: Idling saves gas

Idling may have been the favorite pastime of 19th-century dandies like Oscar Wilde, but it doesn’t help much with fuel economy. In fact, according to Edmunds’ experts, idling could decrease your mpg by as much as 19 percent. Idling for longer than 10 seconds burns more gas than restarting the engine, so if you plan on stopping for longer than 30 seconds, you should turn off your car. (And as an added bonus, you’ll cut back on emissions and help improve air quality as well.) Avoid going idle Wilde and save a few Washingtons in the process.

Gas myth #3: Dirty air filters impact fuel economy

This is true if you drive a ’76 Chevelle, but modern cars have been engineered to control the air-fuel ratio, depending on the amount of air coming in through the filter. Reducing airflow causes the engine to automatically reduce the amount of fuel being used. A dirty air filter may hinder your acceleration speed, but according to Consumer Reports, driving with a dirty air filter no longer has any impact on fuel economy.

Gas myth #4: Cruise control doesn’t improve mpg

Cruise control is still going strong and can actually increase your fuel efficiency. On flat roads and highways, cruise control maintains a steady speed, cutting out rapid acceleration and fuel loss.

Additionally, you can increase your gas mileage by up to 15 percent if you travel at 55 rather than 65 mph. Dropping from 70 to 60 mph improves fuel efficiency by an average of 17.2 percent, and dropping from 75 to 55 improves fuel efficiency by 30.6 percent!

Gas myth # 5: Fuel additives add extra oomph (and gas mileage)

Don’t buy into the advertising. The Environmental Protection Agency tested hundreds of products claiming to enhance fuel economy and have yet to discover one that really works. Your best bet? Skip the additives and keep your car well-maintained.

Hopefully, by knowing what’s myth and what’s not, you’ll be able to maximize your mpg and save some bucks at the pump this year.

Related resources

Green your commute
Drive down your CARbon footprint
Fuel economy by car
Fuel cost calculator

8 Responses to “5 Gas Myths Busted”

  1. Richard E Murray
    March 24, 2013 #

    The easiest way to improve fuel economy is to be sure that the tires are at the pressure specified on the sidewall.

  2. maxentius
    April 16, 2013 #

    Wrong! That is the burst pressure on the tire sidewall. Always refer to your car's owners manual and/or information label in the door jamb and follow that instruction when inflating tires. The tire mfr has no idea what car you're putting their tires on…

    • John J. Publicus
      April 28, 2013 #

      No, the max pressure noted on the sidewall is most emphatically NOT the 'burst' pressure, it's the maximum inflation pressure (it states exactly that right there on the tire sidewall in fact, if you can read).

      Use this pressure if you are carrying a lot of weight. Use about 10% less for a smoother ride without sacrificing mileage or wear. Remember too; tires get very warm with use, especially extended highway use in hot weather. Tire pressure will increase during these times. The rating on the tire is a COLD inflation number, DO NOT adjust your tire pressure when hot to reflect the cold rated pressure. If you must add air during a road trip, adjust it to the pressure of the rest of the tires AT THE TIME.

      And get your information from the manufacturer, not some self imagined 'expert' on some random website…..

      • Mark Caron
        August 7, 2013 #

        the Pressure on teh side wall of a tire is the max pressure that should be put in the tire prior to the bead seating. If you mount tires you need to know this pressure. the best pressure for safty and ride is found on the drivers door panel. NEVER run the tires BELOW the recommended pressure as this can cause the tires sidewall to overheat and fail causeing loss of control, vehicle damage, Injury and Death. remember the Ford Explorers and firestone tires a few years ago.

  3. don robinson
    April 30, 2013 #

    This circular argument leaves out important factors. Take off the blinders. If you're burning fuel at a slightly higher rate, your mpg is lower, but actually since your arrive at your destination sooner and turn off your engine sooner, the same amount of work is done and the fuel use is the same. What I don;t like about slowing down traffic with this argument is that when drivers slow to 55 mpg, other drivers who perceive themselves as speeding when they pass other verhicles will slow down even more. I've seen them on Highway 13, side bay side at 50 mph so nobody else can get by and it creates road rage and other dangerous conditions. The thing that wastes fuel is taigating and subsequent added braking.

    • Colin
      June 21, 2013 #

      Miles Per Gallon does not involve a factor of time. If you drive 300 miles getting 30 mpg, you used 10 gallons. If you drive 300 miles getting 25 mpg, you used 12 gallons. It's simple math.

      I'm going to give you the benefit of the doubt and assume you're confusing cars with boats or airplanes, where fuel consumption is usually measured in gallons per hour (gph). In that case, you're partly right, although higher speeds still tend to result in higher overall fuel consumption – it just can't be measured purely by comparing gph at a given speed.

  4. Ben Sweeten
    November 1, 2013 #

    Myth #1 states that mpg is no different using high octane than low. Can someone explain why I get 41 mpg using Chevron high octane and 36 mpg on low octane fuel. This, by the way is all highway miles driving at 65 mph. Same route, same speed, 4-5 days a week.

  5. MadDog
    November 7, 2013 #

    Because the author is either very misleading or misinformed. She does use the term "most cars" though. It sounds like your vehicle is optimized for premium fuel and doesn't fall into the category of "most cars". If your owners manual states premium, your car will run best on premium. If the manual states regular, your car will run best on regular.

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