Four Gas Saving Myths

I've written a TON about saving money on gas (if you don't believe me, see Saving Money on Gas, Part 1 and Saving Money on Gas, Part 2), but here's a piece that de-bunks some of the (supposedly) most popular gas-saving tips. I'll list the tip, what they (CNN Money) say about it, and my take on the situation. Here goes:

• Tip: There have been additives, special magnets and even a pill that has promised to improve a car's fuel efficiency by as much as 30 percent in some cases.

• CNN Money: Consumer Reports and the government's Environmental Protection Agency, have tested dozens of these products finding that none of them offer any significant improvement in fuel economy.

My take: I'm with them -- I'll pass on the money-saving gimmicks.

• Tip: Leaving your windows rolled down creates an aerodynamic drag on your car, cutting down on fuel efficiency. And there's the notion that the fastest way to drain your gas tank is by running your air conditioning.

• CNN Money: In two separate studies conducted in 2005, the automotive Web site Edmunds.com and Consumer Reports compared the fuel economy of both a sedan and an SUV at highway speeds with and without air conditioning and how open windows affected gas usage. What they found was no significant difference in fuel economy in either sedan or SUV under either condition.

My take: I seem to recall seeing a study that said at city speeds (below 40 mph or so), it was better to have windows open but at highway speed it didn't matter. But for me, I go with the AC no matter what. There's no need saving a few cents if you're miserable in the heat.

• Tip: Some drivers insist the best time to buy gasoline is on a Wednesday, when pump prices have cooled from the weekend run-up when oil companies typically raise prices.

• CNN Money: That's true to a point, says Tom Kloza, chief oil analyst at the Oil Price Information Service. Gas prices tend to be higher on the weekend, but there's no ideal day of the week to purchase your gas.

My take: I've filled up the last two Fridays and I KNOW they charge more on the weekends. Ouch! I'm looking at filling up Monday through Wednesday from now on.

• Tip: It's probably a myth that goes back to the days when cars were equipped with carburetors, but many drivers believe that starting up and turning off your car repeatedly is a fast way to drain your gas tank.

• CNN Money: But because of modern fuel-injection technology, drivers actually save gas by turning off their engine than letting their car needlessly idle, says Consumer Reports' Paul.

My take: So what am I to do with this -- turn off my car at every stop light?

Comments

[Blaine Moore (Run to Win)]

Re: Turning off your car at every stop light - I do (kinda). I don't at every stop light, but if I come to a light that I know is going to be 30 seconds to two minutes long (the average wait time for the lights I hit on anything close to a regular basis if I see it turn red) then I shut off my engine. It makes the vehicle quieter for a few minutes as well, which is nice. I keep an eye on the lights in the other direction, and tend to start my engine a few moments before I get a green (if I'm at the front of the line) or after it turns green (if I can't see the other light or am not at the front of the line).

If I'm not sure how long it'll be or I expect it will be less than a half minute, I just let the engine idle. I realize that I am getting 0 miles per gallon when I idle, but it isn't worth shutting off and turning on for a short stop.

[My New Choice]

Just recently I had been thinking about the windows vs. AC as I primarly drive on the highway, although many times that is at a slow speed. But like you, I simply use the AC when it is too warm as I would rather be comfortable than squeeze a few more pennies out of my gas mileage.

Although I just filled up the other day and my tank of gas cost me over $40 and I have a Scion tC with a 12 gallon tank. Gas in my area is now around $3.60 per gallon so I might need to try and take advantage of more work-at-home days.

[broknowrchlatr]

Mythbusters (Discovery Channel) did 2 episodes on the A/C vs windows down and found that under 40 mph put the windows down. Over 50, use A/C. In between, it doesn't matter much. It depends somewhat on the type of A/C and the body shape of the care. I usually avoid the A/C and drop the driver window and passenger rear window just a bit to get cross-ventilation.

On Wednessday, June 6th, they are testing drafting behind big riggs.

[Alan]

"Tip: There have been additives, special magnets and even a pill that has promised to improve a car's fuel efficiency by as much as 30 percent in some cases."

I find it very frustrating that consumer reports claims additives do not work, when there are hundred thousand dollar independent studies showing their benefit.

http://blog.sfrcorp.com/2006/09/13/do-oil-additives-really-work/

Check out this article before purchasing any oil additive, because it is true that many have false claims giving the good ones a bad reputation.

[Tim]

i love mythbusters and saw the same episode.

the only caveat to stopping and restarting your engine is the extra wear on things like your starter