The automobile
has been a staple of our civilization for a very long time now, most
importantly for transportation. Today, I am going to discuss with you all about
what makes the majority of them move: the internal combustion engine.
History
Karl Benz is
widely considered to be the inventor of the modern-day car. His first design,
named the Benz Motorwagen, was introduced in 1885. Due to their extremely new nature,
these machines were quite costly to purchase at the time, especially for the
average family. It wasn’t until Henry Ford, founder of Ford Motor Company, nearly
perfected the idea of mass-production so cars could be affordable enough to where
even workers on the assembly line could buy one. These mass-produced machines
eventually evolved into the transportation devices we so heavily rely on today.
How They Work
The gas-powered
car is the oldest and most common type. According to the Environmental Science and Technology Journal, “Over 90% of cars
have this type of engine” (Maclean, 2000). There are four steps, or “strokes”
required for the internal combustion engine to create power. They are the intake
stroke, compression stroke, expansion stroke, and exhaust stroke. During the
intake stroke, the piston sits at the top of the cylinder head to maximize
volume in the cylinder, while a mixture of fuel and air is injected inside.
Once this is done, the cylinder moves down. Next, during the compression
stroke, the exhaust and intake valves close as the piston moves back up to
compress the fuel and air mixture. As the piston is moving up to compress the
mixture, a spark plug located at the top of the cylinder ignites. The force of
this ignition causes the piston to move back to the bottom of the cylinder
head. This is called the expansion, or “power stroke”. Finally, during the
exhaust stroke, the exhaust valve opens up while the piston moves back toward
the top of the cylinder, pushing out the remains of the fuel and air mixture,
and eventually out of the car’s tail pipe. This completes the basic cycle of
the four-stroke engine.
Environmental Downsides
The internal combustion engine has been a great thing for us, but it
does bring along some downsides. First would be the gases they emit. In the
article, Going hybrid: An analysis of
consumer purchase motivations, “The
transport sector contributes approximately 14% of worldwide greenhouse gas
emissions and this is expected to increase to 50% by 2030” (Ozaki, 2011). This
air pollution exists partly due to the incomplete combustion of fuel during the
exhaust stroke. The average internal combustion engine uses only a fraction of
the energy it gets from burning gasoline. It leaves behind a mixture of gases that
consists of mostly carbon dioxide, but also carbon monoxide, which is a
colorless, odorless, and tasteless gas that can potentially be harmful to
humans. The carbon dioxide that comes out of your car’s exhaust traps in heat,
similar to the way a greenhouse does, which explains where “greenhouse gasses”
get their name. As internal combustion engines emit more carbon dioxide, this
greenhouse effect grows stronger, and it’s impacting the environment in a
negative way. According to an article from the Alberni Valley Times, there are many consequences that may result
from this greenhouse effect that gasoline powered cars are contributing so
heavily to. There are “warmer oceans, melting glaciers, more violent storms,
[and] changing ecosystems”. Also, the world’s food supply is at risk. The added
heat is destroying food crops and causing problems for fishing. According to
the group DARA International, “climate change and greenhouse gases are cutting
the world's gross domestic product by 1.6% a year” (Alberni Valley Times, 2012). This may raise the price of food in
some countries, but for poorer countries, severe food shortages can occur. DARA
also predicts that about 100 million people will die because of the effects of
significant temperature changes. Another issue with gasoline-powered cars is
the amount of oil they consume. Returning to the Going Hybrid article,
it states, “the transport sector in the industrialised countries
accounts for 60.3% of world oil consumption” (Ozaki, 2011). We have a major dependence on oil that needs
to be reduced drastically. According to Environment America, which is a
nationwide group advocating the use of alternative-powered, cleaner running
engines, “If 75% of American vehicles, including cars, pick-up trucks,
SUVs and vans, ran off electricity, the nation's oil consumption would drop by
about a third” (Doa, 2010). This number is quite shocking, as it really sheds
some light on how much oil gasoline-powered cars use. Having the ability to
potentially cut oil consumption by such a large amount could be a motivating
factor for some people to make the switch to cars that are powered by an alternative
fuel, in addition to the potential health and food disadvantages they
contribute to.
The Engine’s Future
There have been many
advances in recent time to mitigate the downsides of internal combustion
engines and keep them alive in our cars today. Modern technologies, such as
direct injection and variable valve timing, have allowed these engines to use
less fuel to create power, making them much more effective. Some regular gas-powered
cars are getting amazing mileage thanks to improved aerodynamics, less weight,
and smarter transmissions with extra gears to keep “RPM’s” low when cruising. They
are also running cleaner than internal combustion engines of the past, emitting
lower concentrations of those harmful gasses. Another reason they are still so
prevalent is because they can be quite affordable, especially compared to most
hybrid and electric cars. However, as government regulations continue to crack
down on the efficiency and environmental impacts of our automobiles, the
gasoline-powered engine will eventually lose its title as the number one method
of powering our cars. That title will most likely be passed on to their
electric brethren.
Sources
Doa, Lynn.
"Environment America: Electric Cars a 'Potential Solution' to Global
Warming." SNL
Energy Power Daily (2010) ProQuest.
"Electric
Cars can Help Climate, Environment." Alberni Valley Times Oct 12 2012 ProQuest.
MaClean, H. L. Lave, L.B.
"Environmental Implications of Alternative-Fueled Automobiles: Air Quality
and Greenhouse Gas Tradeoffs." Environmental Science and Technology
34.2 (2000): 225-31. Web.
Ozaki, Ritsuko, and Katerina Sevastyanova.
"Going hybrid: An analysis of consumer purchase motivations." Energy
Policy 39.5 (2011): 2217-2227. Web.