Diesel vs. Unleaded: The Truth About Fuel Economy
Ahh, you remember it, don't you? Sitting in the
back of your family's station wagon as a kid, your father pulls up to
the gas pump and a station attendant—an occupation about as extinct as
the dinosaurs—came running out with a rag in his hand, leaned into the
driver's window and said… Diesel or unleaded?
Those days are long gone. And I'm not just referring to the
attendant. Nowadays, at least in the U.S., you can expect to find three
things at a gas pump: self-serve, pay first, and unleaded gasoline
only.
Misconceptions about diesel fuel being dirtier than unleaded gas
several years ago ultimately led to diesel's obsolescence in the more
environmentally progressive United States. Car companies began to
manufacture cars that, for the most part, ran on traditional gasoline.
In response, however, steps were taken to improve the cleanliness
of diesel and now major car companies have begun to sell diesel-powered
vehicles to consumers once again.
In the past, especially in the United States, diesel fuel was
considerably dirtier than unleaded gasoline. Vehicles in the United
States also tended to be built for traditional gasoline, with the
exception of large trucks, buses, and semis. In recent years, however,
steps have been taken to improve the cleanliness of diesel fuel through
regulation, and many companies have begun selling popular consumer cars
that run on diesel fuel.
One such company is Isuzu Motors, known for its popular 5-passenger
Ascender SUV, and two models of high-performing pick up trucks (the
i-290 and i-370). Isuzu's diesel engines have won a laundry list of
awards in past years including Truck of the Year by Motor Trend
Magazine, Executive Diesel Car of the Year 2002 by Diesel Car
Magazine (a publication in the U.K.), Germany's best small and compact
car of the Year 2001 by Mot Magazine (published in Germany), as well
as having been named multiple times by Ward's Communications of the
U.S. as one of the 10 Best Engines. In addition, Isuzu vehicles were
voted the top medium-duty truck brand six times in seven years by truck
dealers. Impressive, but not fully convinced that diesel's better? Keep
reading…
Diesel fuel actually burns more efficiently than gasoline, thus
having a better fuel economy—about 30% more efficient on average. Why?
Diesel is denser than its unleaded competitor. Proponents of
gasoline are quick to point out that diesel engines produce more
greenhouse emissions, which is true, emissions with diesel are about
15% higher than those of traditional unleaded gas due to higher
volumetric energy density. However, the increased fuel efficiency more
than offsets the higher percentage, so in the long run, diesels produce
less emissions— 15% more per gallon used, but a trip in the good ole
family car will use 30% less fuel to get to wherever you're going.
Granted, this wasn't the case with Dad's old wagon. Back then,
before the anti-diesel crusade, diesel engines were creating more
emissions because they simply weren't efficient. Now, with the modern
diesel engine achieving a 20- 40% better fuel economy, it's time to
give diesel a second look.
But that's not the only exciting news about diesel. Originally, the
diesel engine was created as a way to run vehicles using vegetable
oils. While farmers originally couldn't compete with big oil companies,
with gas prices soaring, there's been a renewed interest in alternative
fuel sources—and food-based diesel fuels can be produced quickly,
cheaply, and with the abundance of products grown in our very own
country. These hybrid diesels also known as biodiesel are
compatible with existing diesel engines and can also be made from waste
oils gathered from restaurants or homes—an alternative that serves
several ecological benefits at the same time.
Gina Sarento