Future Transportation Systems - Decreasing Fuel Consumption and Exhaust Gas Emissions in Transportation - page 260

Table 17.1 Prediction for car numbers up to 2050

Year 2020 2030 2040 2050

Number of cars 9 10 9

North America 0.34 0.39 0.41 0.43

European Union 0.27 0.29 0.32 0.35

European countries not in the EU 0.11 0.18 0.20 0.24

Japan 0.09 0.10 0.13 0.15

China 0.09 0.20 0.22 0.24

Other Asian countries 0.11 0.18 0.21 0.24

Other continents 0.19 0.24 0.27 0.29

Total 1.20 1.58 1.76 1.94

shape of the combustion chamber, controlling the combustion, optimizing the
injection, and using a regulated exhaust gas recirculating system.

17.1.1.2 Downsizing the Engine

Downsizing the engine reduces the cubic capacity and the weight of the engine.
However, the use of a very high number of revolutions can increase fuel con-
sumption, especially in very small engines. Driving downsized engines in the best
speed and gear ranges without excessive braking and accelerations saves a high
amount of fuel and emissions [ 4 ].
It is possible to further downsize two- or three-cylinder engines with a Common
Rail system which operate in all ranges of load at the most favorable number of
revolutions especially in starting phases, which are highly sensitive against
irregular running in small highly downsized engines. Electronic control will more
and more support optimal operation in all ranges of number of revolutions and
under all environmental conditions.

17.1.1.3 Turbocharging the Engine

Originally, the charging of piston engines was developed for aircraft engines to
compensate for the reduced air density at higher altitudes and to compensate for
the resulting reduction in the engine's performance. The turbocharger is a special
device which forces more air and fuel into the engine. Unlike the compressor,
which is driven by the crankshaft, the turbocharger is driven by the exhaust gas.
Variable Turbine Geometry makes it possible to regulate the charger pressure to
a large degree. It is primarily used in self ignition engines due to the maximal
exhaust gas temperature of 700-800C (1,292-1,472F).
The exhaust gas temperature of turbocharged spark ignition engines can reach a
dangerously high temperature of 1,000C (1,832F) which is the usable limit of the
advanced materials. These new materials make it possible to use high level of
turbo charging as well in spark as in self ignition engines. Nowadays, for the