ForTwo L3-1.0L (2009)
long as the water is dissolved, it does not have a corrosive effect. Free water causes rust and corrosion to effect both ferrous and non-ferrous metals.
Fuel agents, additives
In order to fulfill the specified requirements, additives are added to the fuel. Gasoline additives are split up into two categories:
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Additives, that are intended to change or improve the fuel's characteristics.
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Additives, that are intended to give the fuel new or additional characteristics.
Here one also has to differentiate between additives for transport and storage purposes, and those that are effective in the engine related combustion
process.
Amongst the additives one counts dyes with which, for safety reasons, leaded fuels can be identified.
The color is not prescribed, but left to the discretion of the manufacturer, who can select specific colors to identify its own fuels by.
The sketched-out gasoline additive process, which is important, in particular, in terms of system purity and protection against corrosion, has enormous
significance in terms of trouble-free and low emission operation in Mercedes-Benz vehicles. The fuel additive should be made available to the customer
at the filling station; we reject the idea of allowing the customer to carry out the additive process on his/her own because this would rule out the
possibility of guaranteeing that the additive was technically in order and appropriate for the fuel grade concerned.
Oxygenic components
Gasoline fuels have oxygenic components added to them for a number of reasons (in the main these are of economical nature, sometimes they have to do
with increasing the knock resistance).
As a rule these are alcohols and ethers; most frequently the alcohols methanol and tertiary butane and as ether methyl.tertiary butyl ether (MTBE) are
used.
Because oxygenic components can alter a fuel's characteristics, many industrial nations have made moves towards governing their usage. The regulations
applicable within the EU will be gone into in detail shortly.
The maximum permissible concentrations of these components, which are also specified within DIN EN 228, are as follows:
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Methanol
3 vol %
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Ethanol
5 vol %
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Isopropanol
10 vol %
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Tert. butanol
7 vol %
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Isobutanol
10 vol %
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Ether (min. 5 C atoms)
15 vol %
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Oxygen content
2.7 percent by weight
The oxygen content refers to the total mass share of oxygen, which is available in the oxygen-containing components in the fuel. As a consequence not
all permissible maximum limits for the individual components can be utilized at once.
The fuel manufacturer is obliged to ensure that all gasoline fuels that contain oxygenic components do not exhibit any disadvantages when compared
with fuels that do not contain oxygenic constituents.
BB00.40-P-0126-00A Sulfur In Gasoline
BB00.40-P-0126-00A Sulfur In Gasoline
- sheet 126.0
1
Origins of sulfur
Mercedes-Benz gasoline engines are designed for gasoline fuels, which comply with respective national / international requirements (EN 228 in
Europe).
These requirement standards normally contain a threshold for the maximum permissible sulfur content, they do not mention the necessary
minimum sulfur content. This is unnecessary because sulfur does not serve any function as part of the gasoline fuel; its presence is primarily down
to specific refinery processes ("cracking process"). The level of the sulfur content in gasoline is therefore essentially dependent upon the refinery's
equipment and operating characteristics which are governed by standards and/or regulations.
2
Sulfur content regulation
2.1 In the EU
For this reason there are no technical objections to operating a gasoline engine with a low sulfur content. This is called for to a greater extent by
environmental reasons. Mandatory within the EU as of 1.1.2000 is a max. 0.015 (150 ppm) and as of 1.1.2005 a max. of 50 ppm. We describe
gasoline fuels with a maximum of 10 ppm sulfur as "sulfur-free".
Sulfur-free fuels must also be available in the member states as of 1.1.05, whereby these have to be available "in a geographically balanced way".
In the Federal Republic of Germany, changes to the mineral oil tax regulations for low-sulfur fuel (max. 50 ppm) that came into effect on