The design of their engines
differs. Unlike gasoline engines, diesel engines do not have spark plugs. Diesel
engines are designed to have a more severe compression of the cylinder contents
during the compression stroke. This results in much higher heating of the
contents. In fact, the temperature becomes so high that the ignition of the
fuel and air becomes spontaneous. Also, diesel engines have this highest
thermal efficiency of any combustion engine, either internal (like in vehicles)
or external (usually non-vehicular).
As a result, their fuel is also a
little different. In the technical sense, the difference between gasoline and
diesel fuel is the length of the carbon chains. Gasoline and diesel are both
types of hydrocarbons (molecules made of hydrogen and carbon). However, diesel
has longer carbon chains.
For those of us without chemistry
degrees, this means that diesel is harder to ignite at ambient temperatures and
needs more compression to ignite. Gasoline evaporates at ambient temperatures,
but ignites most efficiently with a spark. It can also ignite under
compression, as well. Mazda has plans to roll out an engine that utilizes
compression, the Skyactiv-X, in 2019. Diesel was formulated to create more
power for heavier vehicles, who rev less. Whereas, gasoline is formulated for
lighter vehicles who rev more (go faster quicker).
Written by:
Beckie Bean
Digital Content Manager
December 11, 2017
Sources: Chemistry
Stack Exchange, Car
Buyer UK, Wired
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