December 19, 2002
A joint effort on the part of the Japan Automobile Manufacturers Association (JAMA), the European Automobile Manufacturers Association (ACEA), the U.S.-based Alliance of Automobile Manufacturers (AAM) and the United States’ Engine Manufacturers Association (EMA) has produced the third and latest edition of the World-Wide Fuel Charter [see note 1 below].
Discussions aimed at drafting a set of common global standards for fuel quality were launched in 1995, with initial results published in 1998 as the first World-Wide Fuel Charter, or WWFC. A second edition followed in 2000, reflecting global trends in vehicle exhaust emission regulations and the progress made in relevant automotive technologies. The Charter in its latest version represents a finalization of this protracted effort.
Founded on the automakers’ objective of incorporating advanced emission reduction technologies in the vehicles they produce, WWFC has made specific recommendations in four different categories of fuel quality for both gasoline and diesel fuel [2], taking into account regulatory levels for automotive exhaust emissions on a worldwide scale.
The third edition of the Charter, however, proposes revisions in the fuel quality recommendations, determined on the basis of the latest available research data. The most significant of the proposed revisions are as follows.
WWFC also recommends the following maximum sulfur content [5] values for the different categories of gasoline and diesel fuel.
Category 1 | Category 2 | Category 3 | Category 4 | |
Gasoline | 1000 ppm | 200 ppm | 30 ppm | Sulfur-free [6] |
Diesel fuel | 3000 ppm | 300 ppm | 30 ppm | Sulfur-free |
[ppm=parts per million]
[Notes on Names and Terminology]
[1] The World-Wide Fuel Charter
(WWFC)
The World-Wide Fuel Charter recommends global standards for fuel quality, taking
into consideration the status of vehicle emission technologies and the requirements
of automobile users worldwide. WWFC has been established on the basis of extensive
discussions carried out by its membership, composed of the Japan Automobile Manufacturers
Association (JAMA) with 14 member companies, the European Automobile Manufacturers
Association (ACEA) with 12 member companies, the U.S.-based Alliance of Automobile
Manufacturers (AAM) with 13 member companies, and the United States’ Engine
Manufacturers Association (EMA) with 27 member companies. WWFC associate members
are the Association of International Automobile Manufacturers (AIAM), the Association
of International Automotive Manufacturers of Canada (AIAMC), the Associacion Mexicana
de la Industria Automotriz (AMIA), the Associacao Nacional dos Fabricantes de
Veiculos Automotores (ANFAVEA) of Brazil, the Canadian Vehicle Manufacturers’
Association (CVMA), the Chamber of Automotive Manufacturers of the Philippines
(CAMPI), the China Association of Automobile Manufacturers (CAAM), the Korea Automobile
Manufacturers Association (KAMA), the National Association of Automobile Manufacturers
of South Africa (NAAMSA) and the Thai Automotive Industry Association (TAIA).
The International Organization of Motor Vehicle Manufacturers (OICA) takes part
in WWFC in a supporting member capacity.
[2] The Four Categories of Fuel Quality
WWFC has established four different categories of recommended fuel quality for
both unleaded gasoline and diesel fuel, based on vehicle emission control technologies
in use and requirements for reducing vehicle emissions. The four categories are
described in the Charter as follows.
WWFC also recommends the following maximum sulfur content [5] values for the different categories of gasoline and diesel fuel.
[3] Gasoline Lead Content
The third edition of WWFC recommends the complete elimination of the use of leaded
gasoline worldwide, including from markets where the use of lead as a gasoline
additive is allowed. The position of automakers is that the use of lead in fuels
should be eliminated on a global scale as soon as possible and by no later than
2005. For markets with no vehicle emission controls or only the first level of
such controls, WWFC in its previous editions tolerated lead content in trace amounts,
as well as the use of leaded gasoline in specific cases, including wherever its
use was permitted by law. Numerous countries worldwide continue today to allow
the use of lead in gasoline.
Lead, as a metal additive to gasoline, contributes to atmospheric contamination and destroys catalyst-based vehicle emission control systems. Leaded gasoline is therefore a barrier to the introduction of automotive emission control systems that can reduce exhaust emissions by 90 percent or more over uncontrolled levels. Leaded gasoline also impedes the move towards globally harmonized vehicle technologies.
Lead is added to gasoline because of its ability to raise the gasoline’s octane value. In markets where the use of lead has been reduced or eliminated, there are cases of MMT (methylcyclopentadienyl manganese tricarbonyl), ferrocene or other octane-enhancing metal additives being used as substitutes. In its latest edition, however, WWFC recommends a halt to the use of all types of metal additives, based on findings that they are harmful to catalyst-equipped motor vehicles.
[4] Fatty Acid Methyl Esters (FAME)
Methyl esters are synthesized through the chemical reaction (known as esterification)
between rapeseed, soybean or other vegetable oils and ethanol. In the U.S. and
Europe, considerable progress has been made in standardizing the properties of
methyl esters. A significant advantage of FAME content in diesel fuel is that
it reduces exhaust gas particulate matter. However, the disadvantages of methyl
esters are also significant: they require special care to avoid excessive viscosity
at low temperatures and to prevent high water content and the consequent risk
of corrosion. Methyl esters also attack rubber and composite materials in the
fuel system. It is clear that further extensive studies are required on the properties
of FAME as diesel fuel extenders or replacements, including their impact on engine
response.
[5] Sulfur Content in Gasoline and Diesel Fuel
High sulfur content in gasoline contaminates and impairs the performance of catalyst-based
vehicle emission control equipment. High sulfur content in diesel fuel increases
fine particulate matter (PM) emissions and shortens the service life of oxidation
catalysts. Sulfur also is a barrier to the use of NOx traps, diesel particulate
filter (DPF) technology and other advanced diesel and gasoline technologies.
[6] Sulfur-Free Fuels
It is extremely difficult to remove all sulfur content from gasoline, diesel and
other crude oil-derived fuels. This being the case, fuels with sulfur content
levels in the range of 5-10 ppm (or less) are generally considered to be sulfur-free.