With the recent Volkswagen emissions measurement scandal,
are diesel engines really more efficient than gasoline engines?
By: Ringo Bones
Ever since German engineer Rudolf Diesel patented his diesel
engine, the industrial world was quick to embrace it with open arms given that
your typical diesel engine burn about 25-percent less fuel in comparison to a
gasoline engine of similar horsepower rating, not to mention that diesel fuel,
as a byproduct of crude oil refinement, is around 4 to 5 times cheaper than
gasoline when a barrel of crude oil produces 19 gallons of gasoline and 12
gallons of diesel fuel when it is refined. And given this “ energy utilization efficiency”,
diesel engines by their very nature only produce a quarter of the carbon
dioxide produced in a typical gasoline engine – which is now of paramount
importance in our increasingly climate change conscious world. But sadly,
diesel engines are inherently way dirtier than gasoline engines when it comes
to oxides of nitrogen and particulate emissions.
The row over whether diesel engines – as in diesel fueled
cars and trucks – are really more environmentally friendly than their gasoline engine
counterparts recently came to light in the form of the recent Volkswagen
emissions measurement scandal where the famed German automaker was caught by
the U.S. Environmental Protection Agency back in September 21, 2015 when
Emissions Analytics, an internal combustion engine / automotive emissions
testing lab recently uncovered that the latest models of diesel fueled
Volkswagen cars sold in the United States employ a “cheating software” on its
electronic engine management system that automatically reduces the engine’s
power output and thus the resulting emissions output when it detect that the
car is mounted on a tachometer – a device used to statically test the power
output and combustion byproducts of cars under test. The Volkswagen “cheating
software” allowed their late-model diesel cars to produce up to 40 times less
oxides of nitrogen and particulates in a lab testing setting when compared to
being actually driven on the road.
Whether the “cheating” is deliberate or not, from a
scientific viewpoint, diesel engines still produce less carbon dioxide – a potent
greenhouse gas and the primary cause of the ongoing climate change – than their
gasoline counterparts, but the oxides of nitrogen and particulates produced by
diesel engines also have a deleterious effect on our environment and of human
health. The oxides of nitrogen produced by diesel engines can promote the
formation of smog and increases the acidity of rain and can also do nasty
things to our lungs due to its corrosive nature. And also oxides of nitrogen,
the same one that gives a nuclear blast mushroom cloud its orange-brown color,
are usually produced by extreme high-temperature processes that occur in the
earth’s atmosphere both man-made and natural like lightning and the since
retired supersonic airliner Concorde’s Olympus jet engines which can also
deplete ozone in the Earth’s ozone layer giving everyone a higher risk of
getting skin cancer. Particulates that are the byproduct of diesel combustion
can increase anyone with a compromised immune system to catch pneumonia. Diesel
engines may be more fuel efficient and produce less carbon dioxide than
gasoline engines, but clean they are not. Another “environmental fallout” of
the recent Volkswagen Emissions Measurement Scandal is that it could empower climate
change skeptics like the U.S. Republican Party which will eventually point out
that the supposedly earth friendly commercial institutions – like the German automaker
Volkswagen – cheated in order to bolster its green credentials.
