Friday, April 5, 2013

"E" is for Efficiency

Want to know a secret? Ever hear of the famous 200 mile-per-gallon carburetor, the one invented decades ago but suppressed by a cabal of greedy oil company executives? Yeah, it never happened. The mother of all urban legends. How do I know? Simple. It's physically impossible.  Trust me on this.

It’s really not too complicated. There is a certain amount of energy contained in a gallon of gasoline, and it takes a certain amount of energy, and thus gasoline, to safely push an automobile, carrying people and their stuff, over the ground and through the air a given distance at a given speed, and to do so in a structure that won't crumple like an origami boulder upon contact with other vehicles or fixed objects (Smart cars seem a little less so when folded under a semi-trailer).

"I know, but I'm getting wicked fuel economy."
Understand that only part of the energy in a gallon of gasoline is actually utilized in moving the car. Much of the energy is lost - through heat loss, mechanical friction, wind resistance, and tire friction and flex. Even noise and vibration is lost energy. And much of what isn't lost must charge the battery, provide spark to the engine, and power the air conditioning and all those accessories (like Junior and Sissy's DVD players and those front seat bun warmers you paid extra for. Not that there's anything wrong with that).  Even the energy that actually drives the car is eventually dissipated as heat through the brakes. Seriously, the carburetor (or fuel injection today) is not the issue.

Engineers maximize efficiency (minimize energy losses) as much as possible, but no mechanical system is 100% efficient, meaning there are always energy losses. Which is exactly why true perpetual motion machines are an impossibility, the crest of each rise on a roller coaster is lower than the previous one and if you spin the most perfectly balanced and adjusted bicycle wheel it will eventually come to a stop. And because there are always energy losses, there is an upper limit to fuel efficiency and that limit is a lot closer to the highway fuel mileage of a Honda Civic than to a mythical 200 mpg.

All of that awful waste may sound positively medieval, but the truth is, the internal combustion engine is still an engineering marvel that has been refined to fuel efficiency and emissions levels only dreamed of just a few years ago.  We're in the midst of a second Golden Age of high performance, only this time clean and economical performance. (More on that another time.) Electric cars and other alternatives are a real improvement in efficiency, but don't kid yourself; there is still noise and emissions and heat involved, it's just been moved upstream to the coal-fired power plant, conveniently out of sight and out of mind. Internal combustion and alternate energy will exist side-by-side for years to come, like mechanical and electronic wristwatches.  At least until someone figures out how to make a solar-powered airliner.



  1. Here's a thought exercise. What would a perfectly efficient engine be like under the hood? You would have no way of knowing it was running. It wouldn't make a sound. Touch it and it would be the same temperature as the air around you, and you wouldn't feel the slightest movement or vibration.

  2. Very interesting information. I had no idea about the ins and outs of a car's energy but I am always looking for more information and ways to make my driving more efficient. Thanks for the insight!

    AtoZ Challenge Blogger

    1. Thank you for stopping by; I'm glad you liked it. Your blog is excellent; the photography is superb and your "D" post is most worthwhile.

  3. Jerry,
    If there were a 'perfectly efficient engine' would it ever break down? If not, then wouldn't that be a problem for engine manufacturers, never having to replace parts. Kinda like a printer that would never need another ink cartridge?

    1. Good question, I like how you think. Perfectly efficient refers to having zero energy loss, which is different from perfectly reliable. I suppose the latter could be a problem for manufacturers, but I think they make their money from things other than engines, and unreliable engines would bring them more problems than it would money. Reliability brings repeat customers. Ink cartridges are a high-profit item, however, and I'm sure Hewlett-Packard, makes a whole lot of money from them!

      Thanks for stopping by!


  4. A new study has found that home air conditioning played a key role in reducing world death rates over
    the past half-century, by keeping people cool on extremely hot days.

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  5. And yet, air conditioning has become controversial in some circles in developed countries due to its energy consumption. Of course, the use of DDT is frowned upon in those same countries, even though it saved millions in underdeveloped countries from malaria and other diseases. Maybe developed countries should let underdeveloped countries decide what is best for themselves? Thanks for your comments.

  6. All I know about a car is where to put the key to make it go and how to check the fuel level. I'm a big city type who prefers to depend on public transportation. What am I doing in Bakersfield, you ask? Don't ask!

  7. I know what you mean. I wouldn't mind using public transportation in a big city, but it's a pain in places like this. Unfortunately, Bakersfield has a tradition of poor-to-nonexistent transportation planning. There's a lot of work happening now, but it's a bit like improving the barn after the horses have run off.

  8. ..."positively medieval." I won't out you on where you got that quote. :)

    What ELSE is in your head?! And has all this knowledge been pressing against your skull? I'm so glad you're getting it out.

    I can't wait for F. Seriously. I can't even guess where you'll be going from day to day. This is too fun!

    And you write well. Just telling the truth.

    Waiter, drink please!

  9. Please, out me. Seriously, I don't know where it came from.

    I'm a weird person. My brain has conversations with itself about stuff all the time. Some of these posts are pretty old conversations, and yes, it is good to get them out. This challenge and my theme opened the spigot!

    I'm almost done with F, just polishing it up. P will be good, it's geared to writers. I know, I said I'm not planning that far ahead, but my brain had a great conversation about P the other night.

    Thanks so much, Dana.

  10. Intriguing post. Love the title of your blog and I'm looking forward to P!

    Nice to meet you.

    1. Thanks, Jianne! I'm actually going to be changing the name after the Challenge is over. Anyway, I really appreciate the time you took to read and comment.

  11. It came from Disney's Beauty & The Beast. I bet with two daughters, you've had that movie playing in the background at your house once or a thousand times. :) I have.

    Can't wait for P! And I'm still making my rounds for today, so I will go read F now. ~d.


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