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Diesel or Petrol?
When
we use energy, heating the home, driving a vehicle, carbon dioxide is
produced. There is considerable concern surrounding the effect of global
warming and carbon dioxide emissions.
Whichever our choice of fuels available, carbon dioxide will be
produced. Carbon dioxide emissions will be produced in ever-greater
volume as the size of the vehicle engine is increased.
When
fuel is burnt the gasses in the engine combustion chamber are heated and
expand very rapidly to force the engine piston down, on its power
stroke.
The
volume or space into which the burn starts is very significant. A small
volume will produce a greater pressure (for the same amount of fuel) and
as the volume is less there will be less heat loss to the sides of the
combustion chamber.
As the
burning gas expands and forces down the piston, the volume around the
piston increases. The expanding gas comes into contact with the
relatively cool engine metalwork and cools. This cooling effect is a
loss of energy transfer to power and reduces engine efficiency.
When
the process is compared between petrol and diesel engines, the diesel
engine will always be more efficient for comparative levels of
technology.
Why?
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