TFL JUL
19
When servicing the vehicle and the fuel is changed from diesel to bio diesel, the following
applies: the fuel tanks must be cleaned out and initially, the fuel filters need to be changed three
times at around 2000km intervals, and thereafter, as per the requirement as laid out below:
• The interval for the oil and the oil filter change needs to be reduced by 50% (or by half
when normal diesel is used) or after six months, depending which occurs first;
• The fuel filter housing needs to be changed after 12 months;
• Engine mounted fuel pipes and seals need to be changed after 12 months;
• Fuel tanks need to be cleaned after 12 months;
• The fuel level gauge apparatus in the tank and the internal tank filter need to be
changed after 12 months.
“It becomes clear therefore, that with a blend exceeding 5%, the maintenance and servicing factor
is basically doubled, whichwill impact negatively on the lifecycle cost of a vehicle, as well as its level
of up time, in a world where service intervals are getting longer rather than shorter.
“Thus our advice to run optimally, is to stick to the fuel that only has 5% biodiesel content as
per the regulations,” he advises.
According to Eric Parry, Product and Sales Engineering Manager, TG Truck Products, outlines
MAN’s
stand on the issue: “Owing to the lower energy content (compared to conventional
diesel), using biodiesel results in additional fuel consumption of up to five percent.
“Although biodiesel reduces the emission of particulate matter, compared to petroleum diesel,
the content of harmful substances remains comparable to conventional diesel. The emission of
nitrogen oxide (NOx) tends to be higher.”
Since biodiesel contains solvent-like properties, for trucks , special rubber and plastic parts must be
installed in the fuel system. On the other hand, because of biodiesel’s better lubrication properties,
the component wear in the fuel system may be reduced.
Some advantages of biodiesel include: lower complexity and costs for engine conversion;
mixed biodiesel/diesel operation is possible as is alternating biodiesel/diesel – depending on
the cultivation and manufacturing process – and reduction of greenhouse gas emissions may
be a by-product.
Also, there are no problems with handling of the product, while vehicle operating costs can
be lowered.
There are however, a number of disadvantages according to this OEM, the most obvious being
production of biodiesel competing with the foodstuff supply. But so too, damage to agricultural
lands owing to monocultivation and over-fertilisation; high water consumption is required in the
production process; exhaust gas emissions are not better than conventional diesel and there is
additional consumption owing to the lower energy density of the end product.
MAN’s conclusion is: D08, D20 and D26 engine series can be operated with up to 100%
biodiesel when shortened maintenance intervals are observed.
So, is the strive to ‘go green’ enough to change to biofuel? If industry’s view is to be considered,
while biodiesel has its limited place, it’s going to take a while longer before it’s more widely
accepted and indeed, if it is totally accepted at all…
Vegetable oil is used
extensively by the food
preparation industry, but
there is waste from the
process, so vast amounts
of vegetable oil would
be thrown away if not
used for fuel.
