| charliedigital |
http://www.wisebread.com/how-to-sav...r-gallon-on-gas
How to save $0.54 per gallon on gas
Posted April 10, 2008 - 14:25 by Lynn Truong
Filed Under: Frugal Living, Cars and Transportation
slow down
There are many tips that help increase your car's mpg. Hypermiling has been covered, but includes some extreme driving that turns many people off. I also mentioned a few in a previous article, gas efficient driving, that included things like removing items from your trunk, inflating your tires, and keeping your engine in good condition with regular maintenance. But out of all the suggestions, there was only one thing that skyrocketed the mileage on my 2001 Civic from 32 to 47 mpg.
All I did was slow down.
I know that's a tall order for our fast-foward-instant-gratification lifestyle. But imagine getting an extra 15 miles per gallon (that's at least an extra 200 miles per tank). With current gas prices and our slowing economy, it just might be worth taking it easy on the gas pedal.
What exactly do I mean by slowing down? First, let's talk about highway speeds.
In a typical family sedan, every 10 miles per hour you drive over 60 is like the price of gasoline going up about 54 cents a gallon. That figure will be even higher for less fuel-efficient vehicles that go fewer miles on a gallon to start with. - CNNMoney.com
That is based on a $3.25 price per gallon.
In response to the oil crisis in 1973, a 55 mph national speed limit was imposed. 55 mph is still a car's "sweet spot" for fuel efficiency. What uses the most energy of a car at high speeds is the force of air. The increase in wind resistance is exponential, which means it rises more steeply between 70 and 80 mph than 50 to 60. That's why the mpg graph looks like this (from fueleconomy.gov).
I know we're all busy and we've all got places to go. But stop and consider just how much time you're saving by driving faster. If you need to go 30 miles, driving at 60 mph will get you there in 30 minutes. Whereas driving 75 mph will get you there a whole six minutes earlier. On top of that, you used up way more gas for going the same distance!
Increasing your highway cruising speed from 55mph (90km/h) to 75mph (120km/h) can raise fuel consumption as much as 20%. - eartheasy.com
What is six minutes worth to you?
In addition to slowing down on the highway, you can raise your mpg on city streets by doing the same thing. I don't mean driving 10-20 mph, but anticipating stops by taking your foot off the gas pedal to slow down. What uses the most gas when driving on city streets is accelerating. By coasting (taking your foot off the gas and letting your car's momentum move it forward) to a stoplight instead of driving right up to it and then slamming on the brakes does two things.
First, the light may turn green by the time you get there, so you would be accelerating from a coast than from a full stop. Second, you've already used up gas by accelerating to your current speed. If you coast to a stop, the gas the engine already ate up got you further than if you continue to make your engine burn gas just to have that momentum cut short by braking. Going further with less gas is the essence of fuel economy.
It takes a bit of getting used to, because everyone else seems to be zooming by. But if you pay attention, you'll realize that the guy who stepped on the gas just to get around you ended up stopped at the red light that you coasted up to. And if you're usually the guy who weaves in and out of lanes to get past slow cars, you probably never noticed those same cars were still right behind you a few miles later.
Increasing your mpg not only saves money on gas, it lowers our country's demand on oil. If you don't want to give up your SUV, at least make it go further on less gas. So give it shot. You've only got a few minutes to lose. |
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| njjoe |
charliedigital-
Good article.
The author makes several good points.
I can consistently get 30+ mpg on the MO if I stick to 50 mph. Unfortunately, driving that speed on a 55-mph road can get you run over in NJ.
Traffic-light racers waste gallons of fuel. There is a busy thoroughfare a mile from my house that has traffic lights every tenth of a mile or so. They are timed so that if you drive the speed limit you can usually make all the green lights when heading downtown. I always get a kick out of the traffic-light racers who floor it when the light turns green only to have to stop at the next light because it is still red. At the end of two miles I have yet to hit my brakes and am only a car-length behind the traffic-light racer in the Ford F-150 who has hit his brakes hard a dozen times. :4: He's annoyed because he hit every red light :3: and I am relaxed because I hit every green light. :cool: Yet we both traveled the exact same stretch of road at the exact same time. Go figure. :D
-njjoe |
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| Corin |
quote:
Originally posted by charliedigital
Increasing your highway cruising speed from 55mph (90km/h) to 75mph (120km/h) can raise fuel consumption as much as 20%. - eartheasy.com
What is six minutes worth to you?
Well, let's see, is that 6 minutes worth it? They're giving a percentage increase for the fuel consumption, but a fixed number for the time. Let's compare apples to apples, shall we?
First, the 6 minutes saved comes from an example of 60mph versus 75mph, whereas the second example was 55 to 75. So let's fix this first.
Driving 30 miles at 55mph = 32.7 mins
Driving 30 miles at 75mph = 24 mins
Time savings: 8.7 mins (or 26.6%)
Going from 55mph to 75mph is a 36% increase in speed((75-55)/55), and they claim that it increases fuel used by 20% (I'll just consider that a given).
So I'm using 20% more fuel, but saving 26.6% of my time? I don't know, that sounds like a bargain to me. My time is worth a lot, especially when I'm late to work! My hourly salary certainly eats up that difference pretty quick.
(someone check my math, please. My brain is tired, so I'm sure I made a brain-fart somewhere in there...) :) |
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| njjoe |
Corin-
I don't think your analogy works unless you consider the value of your time in dollars, otherwise you are comparing apples (minutes) to oranges ($). Right?
-njjoe |
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| charliedigital |
quote:
Originally posted by njjoe
Corin-
I don't think your analogy works unless you consider the value of your time in dollars, otherwise you are comparing apples (minutes) to oranges ($). Right?
-njjoe
yeah, I think you would have to earn
(or lose) a LOT of money in that 8.7 minutes for it to be a factor. |
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| Corin |
quote:
Originally posted by njjoe
Corin-
I don't think your analogy works unless you consider the value of your time in dollars, otherwise you are comparing apples (minutes) to oranges ($). Right?
-njjoe
True, but the question was: "What is six minutes worth to you?"
And in my opinion, for ME, it's worth the extra money to have more fun driving and get where I'm going faster. More emphasis on the "more fun" part, to be honest.
I'm just saying, to make it easier for the comparison to really compare the cost versus benefit, go off the same scale. 26% time savings for 20% more cost. Whether it is worth that is up to you, obviously, and most likely changes depending on the current situation.
Or, wording it another way, calculate the ACTUAL dollars your spending to get there 8.7 minutes sooner.
Assuming we take the highway EPA rating of 24mpg (for 55mph), and gas costing $3.50/gallon, it would cost $4.38 for the trip (gas costs only, for this purpose). Assuming 75mph will require 20% more gas, doing the same 30 mile stretch will cost a total of $5.25 in gas.
So it's costing you $0.87 to get to your destination 8.7 minutes earlier. (did I do that right? Seems odd that I got 87 for both numbers...)
quote:
Originally posted by charliedigital
yeah, I think you would have to earn
(or lose) a LOT of money in that 8.7 minutes for it to be a factor.
If you want that number in an hourly rate (just for the sake of argument, I know this doesn't really matter) that would be $6/hour.
Now, I enjoy driving. A LOT. And I like driving my MO. I drive spiritedly, and primarily in-town (unfortunately). My overall average mpg for the three years I've had my MO is 18.85mpg (calculated, not the trip computer). I have spent a total of $7,478 dollars to go 46,400 miles. Could I save some money by changing my driving habits? Absolutely. But then again, I could save money by having a more fuel efficient vehicle, or by just taking the bus. In fact, I would argue that I save more by not having my one or two daily starbucks that most people around here are addicted to than what I spend in gas with my style of driving.
I'm not really trying to be argumentative, I'm just trying to show my point of view and how I look at the information presented. Obviously this is different for each person, because it's a value statement.
There are, of course, other points that also comes into play. One is in the last statement of that article, talking about reducing our demand on foreign oil. Another point would be emissions. Generally speaking (not always true, but I believe it is for the MO) if you drive in a way to increase mpg, you're also reducing emissions. You could even try to factor in wear and tear costs of your vehicle (e.g. earlier tire and brake replacement due to spirited driving).
So you really need to consider all these factors:
1) Fun (entertainment expense, if you will)
2) Dollar cost
3) Emotional impact (feel-good about reducing your environmental footprint) |
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| Corin |
Just to beat a dead horse a bit here, I have another example.
I drive across the state a few times per year to visit family. 300 mile drive.
If I go 55mph, getting 24mpg (just as a benchmark) it costs me $43.75 and takes 5.45 hours.
If I go 75mph, the cost increases to $52.50, and the trip takes 4 hours.
I pay an extra $8.75 to get there almost an hour and a half earlier. On a long drive like that, through boring countryside, that seems like a small price to pay for me.... :)
(I wish I could go a steady 75mph the whole way, but with traffic and speed limits on the passes and highways, that just doesn't happen) |
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| charliedigital |
quote:
Originally posted by Corin
Just to beat a dead horse a bit here, I have another example.
I drive across the state a few times per year to visit family. 300 mile drive.
If I go 55mph, getting 24mpg (just as a benchmark) it costs me $43.75 and takes 5.45 hours.
If I go 75mph, the cost increases to $52.50, and the trip takes 4 hours.
I pay an extra $8.75 to get there almost an hour and a half earlier. On a long drive like that, through boring countryside, that seems like a small price to pay for me.... :)
(I wish I could go a steady 75mph the whole way, but with traffic and speed limits on the passes and highways, that just doesn't happen)
Heck, I'd pay $30 (or more) to save an hour and a half of driving time for that kind of distance.
The article just made me *think* about the savings. I may take it a little easier on my daily commute. But for longer distances or the open interstate, like the song says, "I-CAN'T-DRIVE, FIFTY FIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIVE!" |
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| njjoe |
I used to drive from Northern New Jersey to Baltimore every Friday afternoon. :rolleyes: The one-way distance was 210 miles. By averaging 75 instead of 55-mph I would arrive almost an hour sooner, and since I had a very impatient girlfriend waiting in Baltimore, it was most definitely well worth it. ;)
If I arrived an hour later she would spend an additional hour complaining that I was late :3:, so it would end up costing me two hours. :(
I didn't need to put a dollar value on my time to realize it was more cost-effective to arrive earlier. :2:
-njjoe |
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| Corin |
quote:
Originally posted by njjoe
If I arrived an hour later she would spend an additional hour complaining that I was late :3:, so it would end up costing me two hours. :(
HA! Yeah, hard to put a dollar figure on that one! :) |
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