gasoline and diesel engines are the two
most commonly used internal combustion
engines
even though their operations seem
similar they have some interesting
differences and each has advantages over
the other this video is aimed at
exploring these differences and
advantages from a scientific point of
view
both engines have the basic four strokes
intake compression power and exhaust
there are differences between the two
engines due to the difference between
the way fuels burn
gasoline readily evaporates so it gets
mixed with the air efficiently
as a result just a spark is sufficient
to produce smooth combustion in a well
pre-mixed gasoline engine
on the other hand diesel does not
properly mix with air
however if atomized diesel is sprayed
into high temperature air spontaneous
combustion will occur
this means that in gasoline engines the
fuel and air should be pre-mixed
while in diesel engines mixing happens
only during the combustion
this is why diesel engines use a fuel
injector
while gasoline engines use a spark plug
you might have noticed that gasoline
engines are less noisy and vibrate less
compared to diesel engines
this is because the combustion process
in a pre-mixed mixture is smooth and
propagates well
but in a diesel engine the combustion
could begin anywhere in the combustion
chamber and it turns out to be an
uncontrolled process
for this reason to reduce the excessive
vibration and noise problem diesel
engines require a more rugged structural
design than gasoline engines
this is why gasoline engines are always
preferable for lightweight applications
since the diesel engine is compressing
only the air it can achieve a good
compression ratio without risk of self
ignition
but in a pre-mixed gasoline engine such
a high compression ratio is not possible
the higher the compression ratio the
better the efficiency of the cycle this
is the reason why diesel engines have
better fuel economy as compared to
gasoline engines
an interesting question many people
wonder is what if I put gasoline into a
Diesel engine or vice versa
diesel in a gasoline engine will not
even cause firing the reason is simple
diesel is less volatile and will not mix
with the air properly and the sparking
will not initiate any combustion on the
other hand if you put gasoline in a
diesel engine you are spraying a highly
volatile fuel into a chamber of highly
compressed and hot air this will lead to
detonations rather than smooth
combustion eventually the engine
components will get damaged so that's a
big no for gasoline in a diesel engine
thank you for watching the video