show the current and planned vehicle emissions standards in
selected ASEAN countries [12].
3. Fuel quality standards
Fuel quality standards play a crucial role in protecting public
health and the environment from transportation sector emissions.
It is often viewed as an important component of an overall plan to
improve air quality. Between 2004 and 2009, the prices of fuel experienced
large fluctuation. In addition to fuel price fluctuations, cost
uncertainties arise due to the emission of greenhouse gas (GHG).
Therefore, GHG are strongly correlated with the type of fuel. This
correlation gives a rationale for policy proposals such as carbon
taxes, which is translated directly into changes in the price of fuel
[32]. The implementation of cleaner fuels standards has an immediate
impact to the environment when using in both new and existing
vehicle fleets. For instance, the reduction of sulphur to near-zero
levels is prerequisite for any air pollution reduction strategy. In the
United States, lead content ranges in 0.24 g/l of gasoline. In January
2008, some Europe Union countries such as Greece, Italy and Spain
introduced off-road diesel sulphur content permissible maximum
limit to be 1000 mg/kg [33,34].
Fuel quality regulations and specifications vary from one country
to another. Tables 7 and 8 illustrate specifications for unleaded