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 Eco-friendly
deliveries
Studies agree: the main suspect for the attempt on public
health is particulate, minute particles suspended in the air
we breathe and that cause respiratory ailments capable of
leading to illness and even untimely death. The most
dangerous types are those emitted by home heating systems
and internal combustion engines, in particular those diesel
engines that lack antiparticulate filters, especially the
older trucks that also have higher emissions and travel many
kilometers in the city to satisfy the demands of urban
transportation. The problem is made all the more serious by
the economic crisis that prevents the replacement of the
older models with more modern ones that have a lesser
environmental impact. An alternative solutions comes from
Landi Renzo, who has developed a natural gas kit for diesel
engines, the Dual Fuel. In addition to reducing emissions,
it would allow transportation companies to slash their fuel
costs. We tested the solution developed by the experts of
Cavriago on a Fiat Ducato 2011, the 160 Multijet approved as
Euro 4 and lacking the “trap” for fine particulate. This is
the third generation (the fourth went on sale in 2012) of
the historic Fiat model that first appeared in 1981. It is
one of the leading trucks on the Italian market thanks to
its high reliability, the competitive operating costs and
excellent load capacity. This last feature, obvious in the
example we used for the test, an oversize van 600 cm long
and 205 cm wide with a height of 252 cm and a compartment
capacity of 13 cubic meters. This value did not change after
the conversion, because the gas tanks are installed under
the floor: there are three with a capacity of 30 liters each
for a dual autonomy of about 350-380 km. The configuration
recommended by Landi calls for two 40 liter tanks and one 30
liter for a total of 110 liters and 430-460 km of mixed fuel
travel. The system works with fuel combination of a mixture
of diesel fuel and gas, which give it the name “dual fuel”
rather than “bi fuel”, as for the kits for gasoline-gas
conversion. It is a necessary choice: diesel engines do not
have spark plugs and it is therefore necessary to use an
injection of diesel fuel to spark combustion. The control
unit manages the correct fuel mixture which consists of a
quantity of natural gas variable from 0 to 70% (reducing the
quantity of diesel fuel in proportion) depending on various
parameters such as the engine load, temperature and
pressure. The goal is to maximize the use of gas, with
adequate reliability, providing the higher percentage of gas
when the engine load is higher, i.e. when consumption is
higher and the engine is running at close to its maximum
efficiency.
 Gas
intake is inside the diesel fuel refill hatch. The roomy cab
is unchanged, capable of seating three people and designed
to offer the maximum practicality: this is confirmed by the
many compartments of various sizes and shapes on the
dashboard, the arrangement of the controls on the central
console on the left of the steering wheel where the CNG
switch/indicator is located and the simple design of the
instrument panel, containing all the essential information.
The driver’s seat on the Ducato is acclaimed for the comfort
of the seat, designed for prolonged use, and the raised
position that facilitates forward vision. The rear view is
limited by the van size and the absence of an internal
rearview mirror, but the large external rearview mirrors
help, with their diverse curvature radius to provide an
expanded view. The short gearshift lever is very convenient,
installed on the console and practical to use, as well as
accurate in the different positions. Driving this Fiat van
we don’t notice any substantial difference between the two
fuel systems. The most noticeable variation is a greater
availability of power and torque with diesel fuel alone, and
a more silent engine with the addition of CNG. These are
very small differences that made no difference to the
performance of the four cylinder 3 liter, 157 cv and 400 Nm
engine at 1,700 rpm, that enables the Ducato to reach speeds
of 160 km/h and give it good levels of pickup and
acceleration. The big difference is in costs and emissions.
The test drive reveals a consumption with diesel fuel alone
of 12.5 l/100 km, equivalent to a cost per km of 0.212 euro.
With the dual mode the thirst for diesel falls to 4.9 l/100
km plus 3.8 kg/100 km of CNG, a combination that cuts the
cost to 0.125 euro/km. The difference of 0.087 euro/km makes
it possible to recover the cost for the kit with three tanks
for 110 liters (4,317 euro, net of VAT) in just 50,000 km,
which a working vehicle usually travels in a year. The
absence of official data on emissions makes it difficult to
perform an accurate analysis, but we would estimate a
reduction by 15% of CO2 and up to 60% for fine particulate.
La persa di carico del gas è all'interno dello sportellino
del rifornimento del gasolio. Rimane immutato l'ampio
abitacolo, in grado di ospitare tre persone e progettato per
fornire la massima praticità: lo confermano i numerosi vani
di forme e dimensioni diverse presenti sulla plancia, la
disposizione dei comandi concentrati nella consolle centrale
e a sinistra del volante dove è inserito il
commutatore/indicatore del livello del metano e il
cruscotto, dal design semplice e contenente le informazioni
essenziali. Il posto guida del Ducato si fa apprezzare per
il comfort del sedile, pensato per un utilizzo prolungato, e
la posizione rialzata che favorisce la visibilità anteriore.
Quella posteriore è limitata dagli ingombri e dall'assenza
dello specchietto interno ma aiutano grandi retrovisori
esterni con specchi a raggi di curvatura diversi per fornire
un'ampia visuale. Molto comodo il cambio a leva corta
collocato sulla consolle, pratico da azionare e preciso
negli innesti. Alla guida il commerciale Fiat non segna
sostanziali differenze tra le due modalità di alimentazione.
Le variazioni più avvertibili sono una superiore
disponibilità di potenza e coppia con il solo gasolio e una
maggiore silenziosità con l'aggiunta del metano. Si tratta,
però, di lievi differenze che non incidono sulle prestazioni
del quattro cilindri 3 litri, 157 cv e 400 Nm a 1.700
giri/minuto, che consente al Ducato di viaggiare a 160 km/h
e di avere buone doti di ripresa e accelerazione. Molto
diversi i costi e le emissioni. Il test drive ha rilevato un
consumo a gasolio di 12,5 l/100 km, equivalente a un costo
km di 0,212 euro. Con la modalità dual la sete di gasolio
scende a 4,9 l/100 km più 3,8 kg/100 km di gas naturale,
combinazione che riduce la spesa a 0,125 euro/km. Il divario
di 0,087 euro/km consente di recuperare l'esborso per il kit
con tre bombole da 110 litri (4.317 euro, Iva esclusa) in
soli 50.000 km, che un veicolo commerciale di solito
percorre in un anno. L'assenza di dati ufficiali sulle
emissioni rende difficile un'analisi precisa, ma è
verosimile stimare un calo del 15% di CO2 e fino al 60% per
le polveri sottili.
Stefano
Panzeri
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