4 gas-saving "myths"

[Abbey Marie]

4 gas-saving myths

Tuesday May 15, 3:34 pm ET
By David Ellis, CNNMoney.com staff writer
...
So before you attempt a half-baked scheme to stretch your gas dollars, here's a look at what's fact and what's fiction when it comes to fuel economy:

(Additives) Nothing but gimmicks
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.

While the promise of stretching your gas dollars seems awfully lucrative, especially when they cost under $20, most of these products provide a negligible, if any, improvement in fuel efficiency, said Rik Paul, the automotive editor for the publication Consumer Reports.

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.
...

Windows, air conditioning - who cares?
There's the old saw that 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.

Don't believe either one.

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.

Don't wait until Wednesday
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.

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.

Geoff Sundstrom of the motorist organization AAA notes that gas prices fluctuate from day to day and are determined by gas station owners who look at a variety of factors including wholesale gasoline prices, competitors' prices and food and drink sales if they have an attached convenience store.

Restart your engines
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.

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.

Granted it's probably not sensible shutting down the engine every time you get stuck in traffic, but if it looks like you might be at the drive-thru for more than 30 seconds to a minute, it's worth turning off your car, says Paul.

http://biz.yahoo.com/cnnm/070515/050907_gas_myths.html?.v=1&.pf=family-home

[darin]

Don't forget Myth number 1: Light Pressure on the Gas pedal saves gas!
Save gas by accelerating quickly to get up to speed - then MAINTAIN the speed. If you have a manual transmission car, do Near Wide-Open-Throttle, short shifts. For instance, Step on the pedal hard, but shift at 2500rpms, or so. RPMs kill MPG quicker than anything.

When AT speed do what you can to maintain, as the car will use more gas going from, say 60-80mph, than 20-40mph.

:)

[Monkeybone]

tail gate down on the pick-up

[Abbey Marie]

Don't forget Myth number 1: Light Pressure on the Gas pedal saves gas!
Save gas by accelerating quickly to get up to speed - then MAINTAIN the speed. If you have a manual transmission car, do Near Wide-Open-Throttle, short shifts. For instance, Step on the pedal hard, but shift at 2500rpms, or so. RPMs kill MPG quicker than anything.

When AT speed do what you can to maintain, as the car will use more gas going from, say 60-80mph, than 20-40mph.

:)

From the same article as in the original post:

So what are some fuel-savings tips you can trust?

Make sure your tires are properly inflated for starters. Besides posing a safety hazard, underinflated tires can reduce your fuel economy slightly, based on Edmunds.com's 2005 study.

Removing excess weight from your car can also help save you gas. The Department of Energy estimates that drivers can save anywhere between 3 and 6 cents a gallon (assuming gas prices of $2.97 a gallon) just by removing those golf clubs and other unnecessary weight from your trunk.

If your car comes equipped with cruise control, make sure you use it, especially on long trips. Edmunds.com's study revealed that using cruise control at highway speeds offered an average fuel economy savings of 7 percent.

But the biggest fuel saver is driving the speed limit and driving sensibly. Rapid starts and stops and exceeding the speed limit will dent your pocketbook. Just by adhering to one of those, the Department of Energy estimates that drivers can save anywhere between 15 and 98 cents a gallon, again assuming pump prices are at $2.97 a gallon.

[darin]

tail gate down on the pick-up

Actually - at least newer - trucks benefit MORE mpg-wise by keeping the gate UP :)

[darin]

But the biggest fuel saver is driving the speed limit and driving sensibly. Rapid starts and stops and exceeding the speed limit will dent your pocketbook. Just by adhering to one of those, the Department of Energy estimates that drivers can save anywhere between 15 and 98 cents a gallon, again assuming pump prices are at $2.97 a gallon.



I'll get you more info on that, aight?

[Abbey Marie]

I'll get you more info on that, aight?

:salute:

[KitchenKitten99]

I gotta argue about the one on the a/c. If I use a/c, I get less mileage per tank. When I don't need to use it in warm, but not too warm weather, my car gets 375-400 miles out of a tank. When I use a/c a lot, I get maybe 320-340. It really drops if I use it while doing in-town driving.

[Monkeybone]

sorry, i meant that having it down was a myth.

slower starts help save because your engine isn't working as hard i would think

and did you have it on the vent AC or circulated AC? circulated would use more as since you would be making the AC unit work the whole time off of the belt which in turnb makes the engine work harder

[darin]

I gotta argue about the one on the a/c. If I use a/c, I get less mileage per tank. When I don't need to use it in warm, but not too warm weather, my car gets 375-400 miles out of a tank. When I use a/c a lot, I get maybe 320-340. It really drops if I use it while doing in-town driving.

That's a function of your right foot. At-speed (not around town) driving with the AC won't hurt Fuel economy much because once at speed, a car requires VERY little power (50hp? maybe?) to sustain the speed. The drag on the car's engine (load) the AC pump puts out is reduced. Driving around-town, where you're under speed-up-slow-down conditions will likely adversely affect economy. Have a Auto-trans. car? use less gas pedal - just take more time to get up to speed..that may help.

[Abbey Marie]

That's a function of your right foot. At-speed (not around town) driving with the AC won't hurt Fuel economy much because once at speed, a car requires VERY little power (50hp? maybe?) to sustain the speed. The drag on the car's engine (load) the AC pump puts out is reduced. Driving around-town, where you're under speed-up-slow-down conditions will likely adversely affect economy. Have a Auto-trans. car? use less gas pedal - just take more time to get up to speed..that may help.

How about just idling outside my daughter's school for 10 minutes with the A/C blasting?

[darin]

:salute:



It's only in racing — and with exceptions even there — that "revs are free." In fact, entertaining though they may be — and sonorous though they may sound — revs pay a penalty in fuel consumption and in wear.

Also, among the things under your control, one with a most profound effect on fuel consumption is your car's speed. Power requirements grow with the square of vehicle velocity (e.g., double the speed, quadruple the required power). And, obviously, power demanded is directly related to fuel consumed.

Whatever is an enthusiast to do?

When I'm canyon running, corner strafing or, just for the fun of it, beating that fellow next to me across the intersection, I think of my earlier comment about "liquid entertainment." And certainly we have the least expensive gasoline anywhere I'd want to live.

On the other hand, a lot of my motoring is rather more mundane. And there's genuine satisfaction in performing it efficiently.

Remember Coach Grimbly's dictum about "driving with an egg under your foot"? Forget it. The most efficient way to reach cruising speed is wide-open-throttle (WOT) short-shifting. That is, not only do revs cost money, but so does prolonged motoring in lower gears, when throttling and pumping losses are their greatest.

WOT/short-shifting can save as much as 20 percent in city driving, worst to best case. In actual practice, rarely does traffic allow full WOT, but it's certainly fun — and efficient as well — to accelerate briskly through the lower gears to whatever the ambient speed happens to be.

Once there, the appropriate choice of gear is the one that offers modest rpm with relatively large (and constant!) throttle. Here, Coach Grimbly is vindicated. Dithering the accelerator is a pure waste of fuel, as is a slice-and-dice driving style. Read the traffic and go with the flow. Said one of my sources, "In fuel-economical mode, never request more power than is necessary to get to the next deceleration." There's a good enthusiast message here: Once up to speed, maintain it.

And, of course, avoid last-instant braking that wastes both fuel and brake hardware. A word on hybrid braking: It's useful to "shape the stop," that is, not to overwhelm the instantaneous capacity of regenerative braking. What's optimal is a relatively gentle initial pedal, followed by increased pressure as speed diminishes. Some hybrids have regen gauges that help in perfecting this technique.

Last, a lot of this is manual-shift-oriented, but thoughtful mimicking with an automatic can yield benefits as well.

http://www.roadandtrack.com/article.asp?section_id=20&article_id=3424



Read the entire Article. Rather than some 'consumer' reporter, R&T has 'real car guys' - I trust their view more than 'some reporter'.

:)

[darin]

How about just idling outside my duaghter's school for 10 minutes with the A/C blasting?

At idle I bet you'd have NO worse fuel economy w/ the ac on, or off. In a cooler climate - shut the engine off rather than idle for more than a couple mins.

:)

[Hobbit]

Windows down vs. AC and tailgate up vs. down were both tested on Mythbusters. AC is slightly less fuel efficient than open windows, and having the tailgate up is significantly more fuel efficient than down.

[5stringJeff]

The "drive the speed limit (55-60 MPH) for better gas milegae" thing is an absolute myth. I went 70 MPH pretty much my entire road trip and was pushing 40 mpg, which is easily the best mileage I've ever had in my car. Not to mention, it was fully loaded with all my stuff!

[shattered]

The "drive the speed limit (55-60 MPH) for better gas milegae" thing is an absolute myth. I went 70 MPH pretty much my entire road trip and was pushing 40 mpg, which is easily the best mileage I've ever had in my car. Not to mention, it was fully loaded with all my stuff!

Can't be that much of a myth.. If I keep it under 64mph, I get about 30mpg. If I keep it at about 75, I get about 20mpg.

Unfortunately, it's a loooong drive to/from work, so, I'm getting about 20mpg. :(

[jackass]

The "drive the speed limit (55-60 MPH) for better gas milegae" thing is an absolute myth. I went 70 MPH pretty much my entire road trip and was pushing 40 mpg, which is easily the best mileage I've ever had in my car. Not to mention, it was fully loaded with all my stuff!

I think its how consistent you can keep it at one speed. If you keep slowing up then speeding up again you will get horrible gas mileage.

[Abbey Marie]

I think its how consistent you can keep it at one speed. If you keep slowing up then speeding up again you will get horrible gas mileage.

And drive me crazy if I'm behind you!

[jackass]

And drive me crazy if I'm behind you!

Hahahaha...I agree!

[darin]

You guys aren't getting good mileage by obeying or disobeying the speedlimits - you're getting good mileage by maintaining a constant speed :)

[Monkeybone]

it's also the rpm. the higher the rpm the more gas you are using.

[Jon]

The "drive the speed limit (55-60 MPH) for better gas milegae" thing is an absolute myth. I went 70 MPH pretty much my entire road trip and was pushing 40 mpg, which is easily the best mileage I've ever had in my car. Not to mention, it was fully loaded with all my stuff!

Driving 60mph instead of 70, on his drive from Idaho to the Seattle area, my brother gets about 5 more mpg in his Toyota Tundra.

I think that the speed at which you get the best gas mileage varies with the vehicle.

[KarlMarx]

Mythbusters devoted an episode on gas saving gadgets. They proved that most of them were just what you'd expect, a complete waste of money. However, one experiment they did showed great promise. They took an old Mercedes Diesel powered car and, with no modifications other than adding a graduated fuel tank, were able to run it entirely on discarded cooking oil. They got roughly the same mileage as with regular diesel fuel.


BTW Mythbusters is my favorite TV show. It combines the three of my favorite things into a one hour format, technology, pretty girls and explosions!

[Dilloduck]

Only half-fill your gas tank-------less weight to haul around.

[Hobbit]

Only half-fill your gas tank-------less weight to haul around.

Theoretically, yes, but negligible.

[darin]

Theoretically, yes, but negligible.

Righto - gas is what? 6lbs per gallon? 30-60 lbs of fuel won't provide measurable increases in performance. Again - fuel economy is best helped by maintaining speed. :)

[Pale Rider]

Actually - at least newer - trucks benefit MORE mpg-wise by keeping the gate UP :)

Very true. It creates a big bubble of air in the bed that makes it very airodynamic. If you've ever driven a pickup with dry leaves in the bed, you can see this in action.

[Pale Rider]

Mythbusters devoted an episode on gas saving gadgets. They proved that most of them were just what you'd expect, a complete waste of money. However, one experiment they did showed great promise. They took an old Mercedes Diesel powered car and, with no modifications other than adding a graduated fuel tank, were able to run it entirely on discarded cooking oil. They got roughly the same mileage as with regular diesel fuel.


BTW Mythbusters is my favorite TV show. It combines the three of my favorite things into a one hour format, technology, pretty girls and explosions!


Windows, air conditioning - who cares?
There's the old saw that 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.

Don't believe either one.

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.

They also did one where they took matching Ford Explorers out on a race track, put exactly five gallons of gas in both, and ran them around the track at fifty mph, one with all the windows down and air conditioning off, the other windows up with the air conditioning on. The one with windows DOWN and air OFF went around the track almost FORTY MORE LAPS than the one running the air. Pretty convincing that running your air conditioning burns more gas I'd say.

I dig the Mythbusters too Karl. Great show.

[nevadamedic]

4 gas-saving myths

Tuesday May 15, 3:34 pm ET
By David Ellis, CNNMoney.com staff writer
...
So before you attempt a half-baked scheme to stretch your gas dollars, here's a look at what's fact and what's fiction when it comes to fuel economy:

(Additives) Nothing but gimmicks
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.

While the promise of stretching your gas dollars seems awfully lucrative, especially when they cost under $20, most of these products provide a negligible, if any, improvement in fuel efficiency, said Rik Paul, the automotive editor for the publication Consumer Reports.

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.
...

Windows, air conditioning - who cares?
There's the old saw that 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.

Don't believe either one.

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.

Don't wait until Wednesday
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.

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.

Geoff Sundstrom of the motorist organization AAA notes that gas prices fluctuate from day to day and are determined by gas station owners who look at a variety of factors including wholesale gasoline prices, competitors' prices and food and drink sales if they have an attached convenience store.

Restart your engines
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.

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.

Granted it's probably not sensible shutting down the engine every time you get stuck in traffic, but if it looks like you might be at the drive-thru for more than 30 seconds to a minute, it's worth turning off your car, says Paul.

http://biz.yahoo.com/cnnm/070515/050907_gas_myths.html?.v=1&.pf=family-home

The best way to save gas is walk or ride your bike. Maybe even invest in a Vespa, you can ride those around town and they gt tremendous gas mileage.