Reinventing the wheel

The title of this post has been borrowed from the name of a chapter in Natural Capitalism by Paul Hawkin, Amory and Hunter Lovins. A telling segment of the chapter goes:

"The contemporary automobile, after a century of engineering, is embarrassingly inefficient. Of the energy in the fuel it consumes, at least 80% is lost, mainly in the engine's heat and exhaust, so that at most only 20% is actually used to turn the wheels. Of the resulting force, 95 percent moves the car, while only 5 percent movers the driver, in proportion to their respective weights. Five percent of 20 percent is one percent - not a gratifying result from American cars that burn their own weight in gasoline every year."

The contemporary automobile. Efficiency: 1 percent! 1 percent!!! 1 percent!!!!!!!!!!!!!

Maybe you didn't get the message: YOUR CAR IS JUST 1 PERCENT EFFICIENT!

No need to elaborate further, but it is definitely pertinent to look at how vehicles at the Shell Eco Marathon are changing this. The focus of this discussion would remain, however, on Urban Concept vehicles using the Internal Combustion engine.

While unfortunately, no vehicle from Pakistan could post a time last year, let us look at how the teams that excel at the competition manage. For the better - better here having the connotation of technically advanced and financially well-off - teams, the process of removing inefficiencies start at the engine itself. Generally, higher the compression ratio of the engine, higher the efficiency. That's just the basic rule. Then, there are those addressing material choice in the transmission and driveline, modifications in the valve timing, ignition timing and to the minor aspects of the engine. (Pity, I didn't give much attention to the IC egnine teacher)

The better teams would have efficiencies at the engine to be somewhere around 35 percent mark. In efficiencies in the driveline would make the percentage of energy from fuel going into the wheels to be somewhere in the high twenties, even low thirties. This already is a 50% increase in efficiency from the 20 percent figure given above.

Vitally, the vehicles at the Shell Eco Marathon are very light in comparison to the driver. The driver weight may be around a third to even a half of the total weight. (More in the prototype category). Adding in these (yes, they are rough) figures, the we can expect the vehicle to be around 10-20 percent efficient. Thats way way way higher than what our normal cars do. And the start-stop strategy-thing hasn't kicked in yet!

Now, here is one solid reason why you should support the visionaries trying to build these cars!