Toilet Paper & Efficiency

Thumbing through the December 2008 issue of Automobile magazine I stumbled upon the best analogy of efficiency ever. It was in the context of automobile design but it is just as applicable in many other fields. Here’s the quote from Freeman Thomas:

We are getting away from things that are big and learning how to create things that are efficient. It’s like when you get down to that last piece of toilet paper. You really start to think about how you’re going to use it. We’re now at that last piece of TP.

For those who don’t know, he designed the original Audi TT and the VW Concept 1 which became the New Beetle.

Gordon Murray Design T-25 City Car

Gordon Murray's firm is finishing the design of their "city" car, the T-25. The firm plans to license the design to other maufacturers. The claims are that the car will revolutionize mobility and drastically reduce lifecycle environmental impact.
So far it certainly seems to have the potential to do so.

I'm not sure how the car could fit in half a lane to allow two to drive alongside one another, but parking and driving all appear to easily meet the claims .

From looking at the silhouette and dioramas it appears that the car could be used as its own container for transit from the factory to destination. It appears that the front end structure could be a module that could be placed inside the vehicle for shipment, and then bolted to the car once delivered.

FYI Gordon Murray is one of the greatest living automotive engineers, an exceptional lateral thinker. His F1 race car designs have won numerous world championships, the McLaren F1 road car he designed in the early 1990's is still one of the greatest cars by today's standards, and his innovations are numerous. The T-25 will surely become one more feather in an already crowded cap.

http://www.gordonmurraydesign.com/index.html

The Automotive X Prize, Part 2

Looking over the rules further, it seems to me here’s what will happen. The Alternative class will have a lot more vehicles that succeed than the Mainstream class because the requirements are not as difficult.

Fewer passengers, less weight, fewer minimum wheels, and lower performance requirements for top speed, incline, and range. Three wheelers with two front wheels and one rear driving wheel are going to be all the rage. The reasons are because in the US they are legally considered to be motorcycles, and have far fewer regulatory hurdles to clear (airbags, bumpers, etc).

I’m hoping a few four wheelers will make it just to see if it can be done. But I’m convinced the Alternative class will see the bulk of the vehicles that can meet 100 MPGe.

The concepts behind building cars for any of these classes would likely be as follows:

Massive weight reduction. All vehicles will be very light, especially to climb and accelerate during city driving cycles.

Aerodynamic drag and rolling resistance will have to be minimized, so frontal area and drag coefficients will have to be low. But the rolling resistance will have to be high enough to provide adequate braking and cornering traction for the performance requirements. The necessity of these tradeoffs may result in active devices being used to expand the overall performance envelope.

In order to maximize energy efficiency the propulsion method will also use regenerative braking to recapture otherwise lost energy, and reduce the size of the conventional brakes. If an internal combustion engine is used there will be idle cut off and designs will strive to run at a near constant RPM.

The engine will provide only modest power, and will be assisted during acceleration by additional stored energy such as that saved from regenerative braking. Finally, energy captured from waste heat or solar sources will be used for accessory loads. Vehicles using solar sources would have to somehow hedge against extended dark or overcast periods to ensure adequate energy at all times – most likely using the vehicles fuel source directly as back up.