Hypermiling

So at the time of publishing, the #3 most viewed story on CNN features Miles O’Brien’s typical egomaniacal writing directed at a “new” phenomenon called hypermiling. Hypermiling is a buzzword for driving in a way to maximize fuel economy. In short, this article is a good overall idea, kudos to CNN. It promotes conserving energy by changing habits. Upon looking at the substance of the article and the accompanying video, the flaws are pretty numerous and the actual information provided is few and far between. At times reading like a diary entry, the article has more to say about the personal habits of Miles O’Brien than about the philosophy and techniques being pushed by his interview subject, Wayne Gerdes: there are lengthy paragraphs on both O’Brien’s personal plane which he assures us is efficient “as air travel goes” (nevermind that a commercial airliner would be much more efficient) and about O’Brien’s Yukon XL which he mentions he is in no mood to replace. He goes on to do some number-crunching to prove that car-pooling is better than driving alone, and that flying on a full commercial jet is better than driving anything other than an extremely full, very fuel-efficient car. In short, all of these are abundantly obvious. Raising awareness of carpooling and mass transit is important, but burying this in an article about “hypermiling” is odd.

So what parts of this article (and video) are new? The demonstration showcases Mr. Gerdes turning off the ignition at stop lights, even before arriving to them. Although he mumbles something about it being an “advanced technique” it is important to point out that when a car is turned off, it may very well lose power steering and other vital safety features. Replacing a car takes more energy than a drop of gas. Also, remember that there is a surge of energy, both from the battery and from the gas tank required to start a car. One source indicates that it has to be considerably greater than 10 seconds of idling to be better than letting the car run.1 This doesn’t even take account of wear-and-tear on the starter. It takes energy and metal to replace these things. If a driver coasts up to a red light, he probably shouldn’t be waiting that long often. In short, if you are approaching a notoriously long light and see it turn red right in front of you, coming to a complete stop and then switching the engine off may save gas, but turn it back on once the light turns green or you’ll just waste the gas of everyone idling behind you, making the world worse off.

The two also have a great deal of laughs about Mr. Gerdes’ tendency to take corners without touching the brake. In this regard, the brief report simply don’t provide enough information. Yes, American drivers use the brake way too much. I see it almost every day. Some will gun it up to a red light only to brake hard to make up for it. They don’t even touch on starting up and braking gradually or beginning to coast long before the actual turn, all they offer is the dangerous absolutism that drivers shouldn’t brake going around corners. That’s only going to result in more tire wear (wasting rubber) and, yes, more accidents. It should be noted that Mr. Gerdes is driving mostly in wide open suburban roads, where making sloppy turns is less likely to result in an accident.

One gas saving strategy of Mr. Gerdes is downright reckless. As O’Brien mentions in the video, Gerdes drafts behind trucks. This is crazy. Anyone who does it is either crazy or misinformed. You have to get incredibly close to a truck to get a gas mileage improvement. Mythbusters did test this, under controlled conditions and found that the improvement was stunning, but only at extremely unsafe following distances. Plus, during their test, the truck driver and tailgater were able to communicate. In the real-world, it would likely require such variation in acceleration in order to maintain position that it might cost more gas. The fact that someone who is trying to enlighten us about our overuse of the brake pedal would tailgate is poetically ironic. The only way in which tailgating a truck will help reduce one’s environmental footprint is through a fatal accident.

The two repeatedly reference Gerdes’s 50 miles per gallon, “double what Honda promises”, as though these results can be expected for everyone. They seem to be partially fluke, and partially due to his optimal conditions. As usual, CNN’s miraculous solution doesn’t pan out. The fact of the matter is this: Mr. Gerdes is right to suggest that more thoughtful driving can save huge amounts of gasoline, but most of his specific strategies are simply snake oil, and some can be dangerous. Just avoid accelerating up to a red light only to brake immediately afterwards. Start up slowly. Don’t devote several minutes to “warming up the car”; a very little idling is plenty. Turn off the engine, but only if you are confident that you’d be idling for at least 30 seconds.1 Use cruise control on the highway. Don’t wreck your car or someone else’s trying to save .09 cents worth of gas. Above all: Carpool, Carpool, Carpool!

  1. http://www.consumerenergycenter.org/myths/idling.html
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4 Responses

  1. One that i didn’t see here is a little more air in the tires will improve your gas mileage although it may wear out your tires quicker. I think an extra 5 lbs is a good compromise.

    Also, get rid of those fat, knobby tires, they are gas wasters.

  2. Hey Smashed – Let’s make a pact: I won’t tell opine about your turgid prose – so long as you steer clear of things you know nothing about – like how to write an engaging TV story. Deal??

  3. Always nice to have a fan, Mr. O’Brien. Thanks for the comment, but you are more than welcome to opine about my turgid prose, under any name you’d like.
    Rob

  4. Mr. O´brien, something you know nothing about is that news journalism should be about presenting information rather than sensationalizing. This article only steps in to where you have failed.

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