Posts Tagged ‘Fuel Efficiency’

PSST!!!  I know where you can buy gas for $1.25 per gallon less than you are currently paying.  Interested?  Here are directions to my secret gas station: from Maine Street in Brunswick, drive across the green bridge into Topsham.  Turn left on Rt. 196, and right onto I-295 north.  Accelerate at a moderate speed, set your cruise control to 65 mph and, ta-da, you’re there.  


You may have heard rumors that excessive speeding and an aggressive driving style (stomping on the accelerator, slamming on the brakes, and tailgating grandma) uses more gas than driving calmly.  However, you probably don’t think it makes all that much difference.  And, if you’re already a calm driver, you probably don’t think that driving yet more calmly could noticeably decrease your gas usage.  Think again.


Over the course of two recent trips to Boston, I conducted a little experiment.  Our car has a fuel economy display which tells us our average miles per gallon (mpg) over any distance we choose.  I made the drives in segments with the cruise control set at 55, 65, and 70 miles per hour (mph), and recorded my fuel economy for each segment.  On the way back to Maine, I drove the same sections at the same speeds.


The results amazed me.  On segments where I drove 65 mph, I used 25% more fuel than on segments where I drove 55 mph.  Similarly, I used 10% more fuel driving 70 mph than when driving 65 mph.  (Do not try this at home.)


The U.S. Department of Energy’s website (www.fueleconomy.gov) confirmed my experience.  They report that driving the speed limit can save up to 23% on gas usage – the equivalent of paying almost a dollar less per gallon.  Driving calmly, without rapid acceleration and hard breaking, increased the possible fuel savings to 33% (the equivalent of $1.25 less per gallon). 


Another interesting website (www.edmonds.com) posts driving test results on a variety of gas-saving tips.  They found that slightly increasing the time it takes to accelerate from 0 to 60 mph, and braking gently, improved their fuel economy by 25 – 35%.


Even calm drivers can see significant gas savings by calming down just a bit more.  Dropping highway speeds by a few miles per hour, slowing acceleration times by a few seconds, coasting to red lights (when safe), avoiding idling, and not accelerating up hills, can all result in surprising efficiency improvements.


Interestingly, 65 mph, the speed limit on most highways in Maine, is too high to maximize fuel efficiency.  For most cars, fuel efficiency is highest at a “sweet spot” somewhere between 40 and 60 mph.  Every mile per hour you drive above your car’s sweet spot lowers your fuel efficiency.  Larger, heavier cars have lower sweet spots than smaller, lighter cars.  Even my relatively small car used one quarter less gas when driving 55 mph than when driving 65 mph.


Now hold on there, you say.  Doesn’t it take longer to get places when you are driving slower?  It turns out that unless you’re going on a very long trip, or speeding outrageously, you will, amazingly enough, get where you want to go in about the same amount of time.  That’s because the Good Climate Fairy, seeing your virtuous actions, will zip you to your destination just as fast as the Speed Demon. 


Well, no, actually it’s just math.  If you drive 70 mph on your regular commute from, say, Brunswick to Augusta (about 27 highway miles) you will get to work just 1 minute and 47 seconds sooner than if you went the speed limit.  Even driving 70 mph the entire way to Boston (about 110 highway miles) saves only 7 minutes.


Here I am, almost out of room, and I haven’t even mentioned the environment.  In a nutshell, transportation, mostly from our personal vehicles, is responsible for creating one third of all climate-changing greenhouse gasses produced by individuals in the U.S..  If that doesn’t impress you, transportation also accounts for 51% of toxic air pollution and 23% of toxic water pollution (data from the Union of Concerned Scientists).  No other single thing we do as individuals causes as much harm.


Now, let’s say you were, perchance, overwhelmed by all the ways in which you could change your daily behaviors to protect the environment.   Let’s say you thought to yourself, I wish I could figure out one simple thing I could do that would have the biggest benefit for the environment – well, this is it.  You’ve found it.  Take your foot off the pedal.  


There is no other action that is available to everyone (who has a car), is free, is this easy, and that has this large an impact.  The idea that, overnight, we could take a 10, 20, or 30% bite out of the fuel individuals use in driving – without involving anything truly unpleasant, expensive, or complicated – like carpooling with the grumpy guy next door, buying a hybrid, or moving to a smaller house – why, it’s breathtaking.


And one parting thought.  Also on the the government’s fuel economy page, under the heading, “Why is fuel economy important?” is the following sub-heading: “Strengthen National Security.”  Whatever your thoughts about the current conflict in the Middle East, if using less gas now helps prevent some future conflict elsewhere – and there are many reasons why it might – can you think of a more splendid patriotic act?  So, put that flag on your aerial, get out your “Support the Troops” bumper sticker, lobby your legislators for national 55 mph speed limits  – and drive like your grandma. 

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