Hot Articles!!!

The major distinction between diesel and gas lies in
the type of ignition.  While gas engines operate on
spark ignition, diesel engines employ compression
ignition for igniting the fuel.  With compression, the
air is drawn into the engine and subjected to high
compression that heats it up.  The result is a very
high temperature in the engine, much high than that
of gas engines.

In diesel engines, air and fuel are both infused into
the engine at different stages, as opposed to gas
where a mixture of air and gas are introduced.  The
fuel is injected into the diesel using an injector
where in a gas engine, a carburetor is used for this
very purpose.

With gas engines, fuel and air are sent into the
engine at the same time, then compressed.  The air
and fuel mixture will limit fuel compression, and
thereby hence the overall efficiency.  Diesel engines
only compress air, and the resulting ratio can be
much higher.

Advantages
Diesel engines are much more efficient and
preferable as compared to gas engines due to the
following reasons:
1.  Diesel engines have overcome the several
disadvantages of earlier models that featured higher
noise and maintenance costs.  Now, they are quiet
and require less regular maintenance when compared
with gas engines of a similar size.
2.  Diesel engines are more rugged and reliable.
3.  There is no sparking at all as the fuel
ignites.  The absence of spark plubs or spark
wires also helps to lower maintenance cost.
4.  The fuel cost produced is 30 - 50 percent
lower than gas engine fuel prices.
5.  Gas burns hotter than diesel, and
therefore they have a shorter life span when they
are compared with diesel engines.

With diesel engines, the compression ratio is higher
and there is more power.  From a technical point, the
compression ratio of an engine is the comparison of the
total volume of the cylinder at the bottom of the
piston’s stroke divided by the volume of the cylinder
remaining at the top of the stroke.

Gasoline ratios
Serious damage to gas engines can occur if you attempt
to run a high compression ratio with a low octane type
of fuel.  Detonation is the ignition of the fuel due
to the high temperature caused by a high compression
ratio that is developed by design.  The fuel is
ignited prior to the spark of the plugs that result
in a rapid, yet uncontrolled burning.

Diesel ratios
Keep in mind, the diesel is a heat engine, using heat
developed from the compression of air.  High compression
ratios are possible since the air is compressed.  The
hot compressed air is sufficient to ignite the diesel
fuel when it’s finally injected near the top of the
compression stroke.

Diesel engines
Fuel and air in the design of diesel engines are not
premixed outside of the cylinder.  Air is taken into
the cylinder through the intake valve and then
compressed to make heat.  The diesel fuel is injected
near the top of the piston’s stroke in an amount or
ratio that corresponds to the load on the engine.

Heavy duty
The higher compression ratio causes engineers to
design, and test the block, heads, head bolts,
crackshaft, connecting rods, rod bolts, pistons,
piston pins, etc., with a greater range of structural
capacity.  To put it in other terms, diesels are
heavier than gasoline engines.

Gasoline
Deciding on gas and diesel can be tough, although
there are several reasons why you should use diesel.
1.  Diesel engines produce twice the power
per gallon of fuel than gasoline.
2.  A gallon of diesel is normally cheaper
than a gallon of gas.
3.  Diesel fuel doesn’t blow up. The fact
is, its hard to get diesel to burn at all.
4.  Diesel engines will last four times
longer than gasoline engines.
5.  Diesel fuel that is untreated will last
longer in storage than untreated gasoline.
6.  Treated diesel fuel will last longer in
storage than treated gasoline.
7.  Diesel fuel treatment will cost less
than gas treatment.
8.  Spoiled diesel can be reconditioned to
refinery specifications, as spoiled gas can’t.
9.  Unmodified diesel engines can be ran on
vegetable oil.

Most efficient overall - Honda Insight hybrid
With 60 mpg city and 66 mpg highway, the Honda hybrid
has top honors as most fuel efficient in the United
States.  With a 1.0 gas engine mated to an electric
motor, the insight was designed to make the most
of the power by using low resistance tires.  The
bad things about the Insight include a cramped
interior, seating for two, and a very odd styling.

Fuel efficient mid size car - Toyota Prius hybrid
(60 mpg city and 51 mpg highway)
The Prius, unlike the Honda Insight, is capable of
carrying 5 people plus their gear.  The Prius will
generate a total of 110 HP from its gasoline engine
and electric motor.  The sleek shape to the Prius
has a low co-efficient drag although Toyota has
managed to do this with a larger, yet more driver
friendly vehicle than the Insight of Toyota.

Most efficient compact car - Honda Civic hybrid
(49 mpg city and 51 mpg highway)
With a reputation of being the cheapest hybrid in
North America, the Civic hybrid takes the great
design of the regular Civic and makes it a lot more
efficient.  With an output of 110 HP, the Civic
hybrid is very competitive for the class.

Most efficient sub compact car - Volkswagon diesel
(37 mpg city and 44 mpg highway)
The Volkswagon Beetle diesel is ahead of even the
sub compact hybrids.  Making 100 HP, the Beetle
diesel may not sound that powerful, although the
177 lb-foot of torque will put shame on every
other vehicle in the same class.

Most efficient station wagon - Pontiac and Toyota
(30 mpg city and 36 mpg highway)
The Pontiac Vibe and Toyota Matrix are both the
result of a joint venture of Toyota and General
Motors.  Both vehicles come equipped with Toyota
engines, although a lot of the design and
engineering came from General Motors.  Both the
Matrix and the Vibe are versatile with active
lifestyles.  With a fuel efficient 1.8L 4 cylinder
that produces 126 HP, the Matrix and the Vibe
aren’t going to win a street race although they
make up for it with smoothness, efficiency, and
refinement.

Most efficient large car - Hyundai Sonata
(24 mpg city and 34 mpg highway)
The Sonata is a major surprise, beating out very
stiff competition.  The 2.4L 4 cylinder engine is
very smooth, responsive, and powerful.  The
suspension however, is soft, and geared more
towards comfort than handling.  This isn’t a BMW,
although the build quality is great, clearly
demonstrating that Hyundai is no longer a second
rate manufacturer.