
Following our recent article outlining how
biodiesel or
RME (Rape Methyl Ester) could become a viable fuel for farm
machinery, we've had questions from readers asking just who
approves its use.

Here are the responses:
John Deere
John Deere first showed a biodiesel-fuelled 7600 tractor
working on the demo plots at the 1994 Tillage events and revealed
that there was no loss of power through the use of RME.
All tractors produced since 1989 and before the 2002
introduction of common-rail injection systems are capable of
running on pure biodiesel, with some minor modifications.
However, later models fitted with common-rail engines are only
approved to burn a 5% blend.
New Holland
New Holland approves the use of biodiesel blends of up to 20%
(B20). All New Holland equipment currently in production and
powered by CNH engines, including common-rail, can run on B20
without modifications, alterations to service schedules,
restrictions on operating temperatures or additional warranty.
Blends greater than 20% will soon be approved subject to the
purchase of an extended warranty.
Case IH
Although all current
Case and
New Holland tractors use identical power plants, Case only approves
the use of a 5% biodiesel blend for common-rail engines. This can
be extended to 20% for non-common-rail units. Field testing of 100%
biodiesel is under way.
Massey Ferguson
Sisu Diesel engines
that were fitted to most
MF
tractors can run on 100% biodiesel provided the service interval is
reduced by 50%.
Tier III Sisu Diesel engines which use common rail injection
systems can run on a 20% blend of biodiesel. These engines are
fitted to new MF 6400 (6485 upwards), MF 7400 (MF 7485 upwards) and
MF 8400-series.
All Perkins engines used in Massey Ferguson machines can run on
a blend of 5% biodiesel.
Fendt
All Fendt tractors
produced since 1995 can run on 100% biodiesel. Tractors older than
this are capable of handling it with certain modifications -
contact your local dealer.
Latest
Vario
models use Deutz common-rail power-plants. These can also handle
100% biodiesel because they use twin oil-lubricated fuel injection
pumps, thus overcoming the problems of fuel lubrication and rubber
seal degradation.
Because of biodiesel's strong solvent properties it can cause
engine oil dilution. This means oil change intervals must be
halved.
After the first couple of hours with biodiesel, Fendt recommends
changing the fuel filters. For further information, the company
offers a user's manual appendix.
Valtra
Valtra tractors equipped
with common-rail engines can be run on up to 20% bio-diesel. All
other engines can be run on up to 100% biodiesel.
Engine performance with bio-diesel is the same as with mineral
diesel.
Sister-company Sisu Diesel is continuing tests with biodiesel.
It is possible that greater concentrations of biodiesel could be
used in the future. The previous limit for common-rail engines was
a blend of 5% biodiesel.
Valtra's engines do not need to be modified before using
biodiesel. However if a blend of more than 5% is used, the engine
oil, oil filter and fuel filter must be changed twice as often as
normal.
In addition, Sisu Diesel recommends that a separate pre-filter
be fitted if biodiesel is used regularly. The water filter should
be checked frequently, as biodiesel is more liable to absorb
condensed water than normal diesel fuel.
| DO THE FIGURES STACK UP? |
Not including fuel duty, biodiesel production costs currently
hover around the 50-60p/litre mark. Because mixing the fuel with rebated red diesel can affect the
dye, blends attract a duty rate of 53.27p/litre - over 6p more than
the standard road fuel rate. Clearly both the production and tax costs make biodiesel's use
as an agricultural fuel unviable for now. However with the Chancellor's pre-Budget report likely to
announce a review of the duty situation for blends and as mineral
diesel prices continue their inevitable upward spiral it's likely
to become a more attractive
proposition. |
Same Deutz-Fahr
All tractors marketed under the
Deutz-Fahr, Same,
Lamborghini and
Hurlimann
brands equipped with Deutz engines are now able to run on fuel
blends containing up to 100% biodiesel.
The key to this is the engines' fuel injection systems, which
use injectors fed from individual pumps. Deutz says that this is a
system which can guarantee reliability when operating with
biodiesel.
McCormick and Landini
All
McCormick and
Landini engine suppliers -
Perkins,
EEA and
Cummins
- allow the use of a biodiesel blend of no more than 5% Methyl
Esters and 95% EN 950 mineral diesel fuel. Conditions apply,
including fuel storage methods and engine servicing intervals.
Regular oil sampling is recommended. Failures that can be
attributed to operating with biodiesel will not be covered by
themanufacturer's warranty.
Perkins
All current Perkins engines can run on a 5% biodiesel mix
without loss of performance or warranty invalidation. Although the
energy content of biodiesel is 8-10 % lower than that of
conventional diesel, at a 5% blend any loss of power will be
negligible and operators are unlikely to notice any marked
deterioration in performance.
Service intervals will remain at 500 hours or as otherwise
previously specified.
Trials of fuel with a higher proportion of biodiesel are ongoing
and Perkins expects to make a statement in the New Year.
Cummins
All recent Cummins power-plants (as used in McCormick and JCB
tractors) are capable of handling up to 5% biodiesel.
The company is looking at the possibilities of increasing
this.
Biodiesel has an aggressive solvent nature. This, combined with
the reduced lubrication properties of low sulphur mineral diesel,
can have a detrimental effect on fuel injection system seals.
| FUEL QUALITY IS KEY |
All the major manufacturers were keen to point out that RME must
meet EN 14214 specifications. Unrefined cold-pressed vegetable oils are not included in any
brands' biodiesel approval. A group of fuel injection specialists, including Bosch, Delphi,
Siemens VDO and Denso, warn about the quality of the final
fuel. Of particular concern is the oxidative stability of blends. When
mixed with low sulphur diesel, biodiesel can become more prone to
deterioration. This means that the fuel can become dangerously corrosive and
gums can form to block filters and cause coking. Biodiesel can also corrode painted surfaces, plastics and
rubber, so extra caution should be taken when filling the fuel
tank. On the other hand, biodiesel degrades naturally, so any
overflow can be rinsed off. |