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Thursday, 21 February 2008 13:00 |
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On 3 March, 2005, the South Africa Cabinet approved cleaner
fuels for South Africa. This legislation has been effective 1
January 2006. Traditionally, Robin Subaru petrol engines users
have been using leaded fuel. In this article we take a look at
unleaded (ULP) and Lead Replacement Petrol (LRP) and the changes
needed for Robin Subaru engines to operate effectively with new
fuels.
Lead has been used in fuel since the 1920"s. During normal
operation of petrol engines, "pinging" or "knocking" takes
place. Engine knock takes place when the last part of the
air-fuel mixture in the combustion chamber detonates
uncontrollably - this may damage the engine. In order to prevent
"knocking", petrol requires a certain octane level. The octane
rating of fuel is a measure of its resistance to cause knocking.
The higher the octane rating, the tendency of knocking will
occur. So lead has been added to fuel since 1920, as it was a
cost-effective way to boost fuel´s octane rating.
With technological advancement, emerged a greater awareness of
environmentally friendly vehicles. Nowadays the design of
vehicles using catalytic converters is standard practice. Leaded
petrol cannot be used in vehicles using catalytic converters so
unleaded petrol has been introduced in South Africa in 1996. The
added bonus of using unleaded fuel, is that it does not emit
harmful lead into the atmosphere which could adversely affect
human health and the environment. Another advantage to vehicle
or engine owners is that unleaded petrol does not result in
formation of corrosive elements, which cause damage to spark
plugs and exhaust systems. This will reduce maintenance costs.
So, which types of fuel will be available? Government
determined that 3 type of unleaded fuel (ULP) will be
manufactured:
91 Research octane number 92 Research octane number 93 Research
octane number
The use of different octane levels will differ based on location
- for example:
If you live below 1,200m above sea level 91, 93 and 95 graded
ULP will be available. At this altitude 95 LRP will also be
available for use. Living at an altitude higher than 1,200m
above sea level will allow for 91,93 and 95 graded ULP with 93
LRP. Therefore the altitude determines the type of ULP or LRP
that will be available.
Unleaded petrol is generally suitable for lawnmower, motorbike
and outboard engines. It is however advisable to contact your
manufacturer to confirm the best type of petrol to use in your
particular engine.
What about Robin Subaru engines? Goscor Engines divisions
announced that the phasing out of leaded petrol would not be a
problem for Robin Subaru engines.
They recommend that engine owners decide on the most appropriate
unleaded petrol (ULP) or lead replacement (LRP) petrol using
only that petrol grade for their engines. It would not be a good
idea to keep on switching between the different grades
available.
If for some reason the grade of fuel used needs to be changed,
users will have to take their engines in to the nearest service
center for the engine to be de-coked. It is a simple procedure
where the mechanic removes the cylinder head in order to remove
all the carbon from the cylinder head to back lap the valves.
It is not advisable that engine owners do it themselves
especially when service warranties are still valid. Existing
Robin Subaru engine warranties will stay in tact during the
phasing out of leaded fuel on the condition that engine owners
submit engines at service centers for the de-coking of engines.
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