Ronin of the Spirit

Because reality is beautiful.

One bazillion miles per gallon

So, I really don’t have much to say tonight, but I don’t want to blog tomorrow, because I have spent the whole evening answering emails tonight and I need to spend some time with my daughter tomorrow.

So, here is the Aptera

Its a slippery little car made by a composites company.  It gets 300 mpg.  (Actually it doesn’t, more on that latter.)  It looks funny because for a car it has obscenely good aerodynamics.  Drag coefficient is a what is called a dimensionless number, or what I think of as a magic number.  No mater how big or small something is, it’s shape has a C/d.  The lower the C/d the less energy it takes to push the shape through the air.  (The truth is bit more complicated, but thats pretty much it.)

The C/d for the Aptera is 0.11.  Now, that is very good for a car.  The Honda Insight (which is no boxy fuel hog) has comparitively icky 0.25.   However, a Boeing 747 has 0.0331.  If a 747 and the Aptera had the same cross sectional area, the Aptera would take 3 times more energy to go the same speed as the 747.

This is where that whole 300 mpg thing ties in.  The Aptera doesn’t get 300 mpg.  It gets 120 mpg.  When being used as a plug-in-hybrid it gets 300, but the straight performance is 120.  (For more about plug-in-hybrids click here) And, quite frankly, 120 isn’t good enough for a vehicle that must be licensed as a motorcycle.

Here is a car that gets 75 mpg, seats 2, and is street legal.  It was also made by some dude in his garage.

Out of a 1989 Geo Metro.  See, when some guy with a hacksaw can make an insurable, drivable, 4 wheeled car, that meets all the crash and emissions standards for its year of manufacture with no engine modifications…

Lets just say I am a little suspicious that 120 out of pure carbon fiber is really even trying that hard.  May I remind everyone, that elite cyclist have a maximum output of about 2000 watts in a sprint.  The land speed record for a fully faired bike is…81 mpg.  On 2.6 horsepower.  The Aptera is cool.  I hope they sell.  But we can really, really, do better.


April 18, 2008 - Posted by | Ecology, Microcar, skepticism, Small Car, Uncategorized | , , , , , , , , , , , , ,

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