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Don’t Run on Empty, and New EPA Stickers for New Cars

This article was written by in Consumer. 15 comments.

Before my girlfriend purchased a new car, she was always careful to refuel her old car before the gas gauge dipped below a quarter of a tank. I’ve been living on the edge, letting my gauge drop to one-eighth of a tank or less before refueling. Her concern was that the gauge didn’t seem very accurate; the needle traveled from one quarter to empty much faster than it moved from full to three quarters. No one wanted to be stuck on the side of the road without gas in the tank.

Consumer Reports offers some tips to avoid the damage you could cause to your car by letting the fuel tank approach empty.

  • Keep your gas tank no less than one quarter full.
  • Fill up before heading out on a long trip or to work as you could get stuck in traffic and have a longer ride than intended.
  • Don’t rely on your car to tell you how many miles are left, as those range numbers can be deceiving and run down quickly, depending on how you drive.
  • We all want to save money at the pump, but instead of driving miles away to the gas station, use online tools or even smart phone apps to find the cheapest gas near your house.

In addition to these tips, the article explains the mechanical problems that could result after not applying these suggestions. Of course, you could avoid some of these problems by moving from gasoline fuel to electricity. Electric cars may not be perfect replacements right now, but they do offer a way to distance a driver from oil companies and gas stations. In addition, electric cars will benefit from the newly designed EPA window stickers.

The new stickers have more numbers to understand. The sticker pictured here applies to gasoline vehicles, but electric vehicles have a sticker with even more numbers, including a measurement called MPGe, the equivalent MPG in a gas-powered car. The best electric cars get 99 MPGe.

These new stickers allow you to compare an estimated annual fuel cost as well as how much you would save per year compared to the average car in any particular vehicle class. What’s even more interesting for technologically savvy buyers is the QR code. Each sticker contains a QR code that can be scanned by mobile phones. When the code is scanned, it will bring you to a government website where you can use the car’s data to customize the calculations of cost based on your personal usage and driving habits.

The EPA stickers for gasoline-powered cars include a new calculation called gallons per 100 miles. This can be a more effective calculation for comparing vehicles because it takes into account the fact that a one mile-per-gallon difference between gas guzzlers is more significant than one mile-per-gallon difference between more economical cars. For example, while the difference between 20 MPG and 25 MPG is the same as the difference between 35 MPG and 40 MPG, if converted to gallons per 100 miles, the difference between the less fuel efficient cars (5 GPHM vs. 4 GPHM) is more than the difference between the more fuel efficient cars (2.86 GPHM vs. 2.5 GPHM). This type of calculation makes more sense when you consider that most people have a constant driving distance. People don’t base their driving on the gallons they’d like to use, so that is a variable. The constant belongs in the denominator; in other worse, GPHM is better represents the reality of driving.

Photo: vallis-clausa
Consumer Reports

Published or updated May 26, 2011.

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About the author

Luke Landes is the founder of Consumerism Commentary. He has been blogging and writing for the internet since 1995 and has been building online communities since 1991. Find out more about Luke Landes and follow him on Twitter. View all articles by .

{ 15 comments… read them below or add one }

avatar 1 rewards

What are the mechanical problems when driving with less than 1/4th of a tank?

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avatar 2 Luke Landes

From the Consumer Reports website linked in the article:

The gasoline acts like a coolant for the electric fuel-pump motor, so when you run very low, this allows the pump to suck in air, which creates heat and can cause the fuel pump to wear prematurely and potentially fail. The repair could end up costing a couple hundred dollars to fix — much more than the $4.00/gallon fill up. Also, if there is dirt in the fuel tank, it could lead to blocking the fuel filter; again, another expensive repair.

Also, there’s the danger of running out of gas while you’re driving, getting stranded, and getting killed by a passing car with a driver who’s fiddling with his cell phone while you’re parked on the shoulder of I-95 waiting for AAA, but that’s less technical and more… mortal.

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avatar 3 Anonymous

I’m not a mechanic by any means, but I find this hard to believe. If running low was really a problem for the fuel pump…it would be listed right there in the manual along with the other warnings – it’s not (at least not for the cars I’ve owned). Also…the fuel pump…well it pumps fuel, it’s only going to suck in air…if your basically out of gas – not just under 1/4 tank.

The only reliable bit of info I know about this is that sediment can collect in the tank sometimes…so running close to empty can suck that stuff back up. However, if like myself, you *always* run the tank to nearly empty that’s not a problem.

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avatar 4 rewards

I’m not a mechanic either, but according to the reputable source known as CarTalk (as opposed to Wikipedia) the idea that running near empty will suck up sediment is a myth. They say that gas tanks are emptied from the bottom and not siphoned off from the top.

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avatar 5 TakeitEZ

I have a bad habit of waiting until my car is almost on E before I fill it up again. I have had situations when I am driving on Rt. 78 E in the morning to work and hit some unexpected traffic and get all stressed out hoping my car doesn’t conk out due to lack of fuel.

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avatar 6 Anonymous

I’ve been there…I love it when I decide to go to the next service station…even though I’m already low…and then there’s the wall of traffic. Keeps you awake if you were sleepy though!

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avatar 7 wylerassociate

i’m just wondering given the price of gas increasing, just how much money can a person save using online tools like gasbuddy or smart phone apps? I get 10 cents off the gallon when I use my grocery card at a Circle K station but has anyone found any better deals?

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avatar 8 shellye

I commonly run the tank to empty. For me, the weather usually plays a role in when I fill up. If it’s freezing cold and windy outside, I’ll delay it as long as possible (I know it’s a bad habit!), or conversely, if it’s hot outside, I’ll wait until a cooler time of day, or at least when I have some shorts on. LOL. Very silly, but very true. Thanks for the info.

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avatar 9 Anonymous

I generally fill up when I have roughly 3 gallons left (15 gal. capacity Tank). I guess I am pushing it a little, but my car is 16 years (160K miles) old and doing fine! I often heard you don’t want to go too low due to sediment at the bottom of your tank?

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avatar 10 rewards

Speaking of saving money on gas, is it a myth or is it reality that ethanol blends lower your mpg? If so, is there a site that tracks stations that don’t spike their gas with ethanol?

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avatar 11 Anonymous

This is an interesting subject for a non-mechanically inclined person such as myself, one
that should be EASY TO RESOLVE! I’ve heard about the rust flakes and other sediment getting
sucked into the fuel pump and damaging it, but I always thought the tank fed from the bottom
all the time. If this is true, WHY is Consumer’s Reports spreading an urban legend when they
should be debunking it? If it is NOT true, why doesn’t the owner’s manual mention the danger
to the fuel pump of running the tank low? Inquiring minds want to know!

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avatar 12 qixx

Rust flakes would float on top of the gasoline. They would only be picked up when empty. Dirt would sink to the bottom and get sucked up quickly.

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avatar 13 Cejay

Nevedr knew that fact about driving on less than 1/4 tank of gas. I just kept it filled up since , like your girlffriends, it seemed to drop from 1/4 to e awfully fast. But now I have a much newer car and the only problem is that I could not afford to pay cash for all of it so I have a payment.

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avatar 14 GraduatedLearning

The best way that I’ve found to improve my gas mileage is driving a steady speed. I’ve gotten near 40mpg in my Corolla when I’m going long trips at 55-70 miles per hour. I don’t think I’d consider myself a hypermiler, but I try not to decelerate or accelerate too much.

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avatar 15 skylog

i like the idea of the stickers. perhaps they are overkill for some, but the more information the better as far as i am concerned.

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