Environmental Engineering Reference
In-Depth Information
move beyond
mpg are already in the works or exist. Here
are a few examples (see [
] for more detail). Note that the
actual requirement is on emissions and is
grams of CO
(about
ounces) per mile in
. When it is achieved, oil
import will go down by about
million barrels per day
making the United States nearly self-suf
cient in oil.
Diesel engines in Europe have about
% better fuel
economy than gasoline engines (operation is at higher
compression ratios, and diesel fuel has more energy per
gallon than gasoline).
HCCI (Homogeneous Charge Compression Ignition)
engines run on gasoline but have the ef
ciency and fuel
economy of diesel engines; they are being developed by
most car manufacturers.
Every
% weight reduction produces a
% improve-
ment in fuel economy.
Weight and Safety
There is a concern that reducing vehicle weight will result
in more injuries in crashes. However, crashworthiness is
largely in design, not in size or weight. A report by the
International Council on Clean Transportation [
]
(ICCT) breaks safety into three components: crash-
worthiness, crash avoidance, and built-in aggressivity (a
wonderful term that I had not heard before).
All passenger vehicles are crash tested and rated for
crashworthiness using instrumented dummies to simu-
late what would have happened in real life. You do not
have to be big to be good. The very small SmartCar
made by Mercedes has a high crashworthiness score.
