Diesel Versus Spark Engine Ignition

As you may already be aware of, diesel engines are

more efficient than gasoline engines of the same

power, resulting in much lower fuel usage. For an

efficient turbo diesel, the average is 40% more miles

per gallon. The higher compression ratio with

diesel engines help to raise efficiency, but diesel

fuel also contains around 15% more energy per unit

volume than gas.

Diesel engines that are naturally aspirated are far

more massive than gasoline engines of the same power

for two reasons. First, it takes a larger capacity

diesel engine than a gas engine to produce the same

amount of power. Essentially, this is because the

diesel can’t operate as quickly. The rev limit is

slower, because getting the correct fuel to air ratio

into a diesel engine fast enough is more difficult

than a gas engine. The second reason is due to the

fact that a diesel engine needs to be stronger to

withstand the higher combustion pressure needed for

ignition.

Diesel engines also produce very little carbon

monoxide as they burn the fuel in excess air except

at full loading capacity, where a full quantity of

fuel is injected per cycle. They can however,

produce a black soot from the exhaust, which consists

of unburned carbon compounds.

Often times, this is caused by worn injectors, which

don’t atomize the fuel sufficiently enough, or a

faulty management system that allows more fuel to be

injected that can then be burned with the available

air.

For commercial use that requires towing, diesel

engines tend to have more desirable torque. Diesel

engines tend to have their torque peak quite low

in their speed range which provides smoother control

over heavy loads when starting from rest, crucially

allowing the engine to be given higher loads at low

speeds than a gas engine.

The lack of an electrical ignition system in diesel

engines improves the reliability. The high durability

of diesel engines is also due to the overbuilt

nature as well as the combustion cycle, which will

create a less violent change in pressure when

compared to a gasoline type spark ignition engine.

Diesel fuel is also a better lubricant than gasoline,

so it is less harmful to the oil film on piston

rings and cylinder bores – making it routine for

diesel engines to go 250,000 miles or more without

having to be rebuilt.

For several reasons, diesel proves to be better than

spark engine ignition. Diesel engines last a lot

longer, they offer more torque, and they are also

more reliable. They are also more expensive as well,

although you get what you pay for. If you have

never owned a diesel vehicle, you owe it to yourself

to see everything they offer you – and you’ll find

yourself a very satisfied customer.

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