The web economy blog

Archive for October, 2011

As a result of the current economic trends Have you been toying with the idea of purchasing or renting a new SUV or changing over to a more fuel-efficient model, it’s imperative to know that you may not be comparing apples and apples. Just recently the Environmental Protection Agency or the EPA as we know it has a brand method of calculating the fuel economy of the new cars as well as pick-ups and SUVs.

The main reason that the words fuel and efficiency are on the tip of almost everyone’s tongue is simple; in fact it is the main cause for change in so many situations, its cash. As the global economy crashes and the amount of natural resources’ in the world dwindle the price of petrol rises.

A few years back, the EPA, together with automobile manufacturers, used a method of testing a vehicle’s fuel economy, that let’s just say, didn’t satisfactorily recreate real-world conditions. The vehicle was placed on a set of rollers called a ‘dynamometer’ that allowed the car to sit in place while turning the wheels of the vehicle. Although the drag on the rollers was adjusted to better simulate various driving conditions, the vehicles were never tested in an environment where wind resistance could manipulate the amount of fuel being burned, and the accessories were never running. Hence, the test created a level playing field for all vehicles of the same class to be compared, but the results never depicted the fuel economy you could expect in the real world. What’s more, the simulated speeds a few years ago were noticeably slower than what the normal driver actually drives today. It was something like only forty eight miles per hour for highway tests and twenty miles per hour for tests in the city. These conditions were not really effective when checking for fuel economy.

Beginning now, the Environmental Protection Agency has started using an adjusted system of testing requirements to account for all the things that affect fuel economy: faster acceleration, higher speeds in both the city and on the highway, colder external temperatures, and vehicles are now tested with accessories (such as heating or air-conditioning) turned on.

A lot of automobile manufacturers have upgraded their lines to be more fuel-efficient as a response to amplified gas prices over the past two years. However, on paper, the fuel economy of these vehicles seems to be much worse than its predecessors. Without an understanding of the new testing system, comparing one’s older model to a new 2008 could suggest you’re better off keeping the car or pick-up you have. Chances are, you’re not. Even the “non-green” models (models that still operate solely on petrol with no the support of an electrical power source) are becoming progressively more economical.

So what is the moral of the story? Comparing older models to previous years does not tell you a lot in terms of fuel economy, so stick with comparing between the new models to determine if the SUV or car you’ve got your eye on stands up to the other vehicles in its class.

In this case when we say Fuel Economy, we refer to the fuel efficiency relationship between distance traveled by an automobile and the amount of fuel consumed.

Fuel Economy – The Good Old Days

You do remember fondly, don’t you? lounging in the back of the family car as a child, your dad pulls up to the gas station and a gas station attendant (an occupation about as extinct as the T-Rex) comes running up with a rag in his hand, leans into the driver’s window and says… “Will that be Diesel or unleaded?”

Well, those good old days remain just that..Good old days. And I’m not just referring just to the gas station employee. At the present time, at least in the United States you can expect to find three things at a gas station: self-service, pay up front and unleaded gasoline.

The age old misconception about diesel fuel being “dirtier” than unleaded gas more than a few years ago eventually led to diesel becoming obsolete in the highly environmentally progressive United States of America. Car manufacturers began to produce cars that, for the most part, ran on traditional gasoline or petrol.

However, the car companies reacted to this and steps were taken to develop the cleanliness of diesel and now the foremost car companies have begun to sell diesel-powered vehicles to consumers once again.

In the days gone by, particularly in the United States, diesel fuel was significantly dirtier than unleaded gasoline. Vehicles in the United States also were mostly built for traditional gasoline, with the exception of big trucks, buses, and semis. In recent years, however, steps have been taken to improve the cleanliness of diesel fuel through regulation, and many car manufacturers have begun selling popular consumer cars that run on diesel fuel.

A well known company is Isuzu Motors, known for its trendy 5-passenger Ascender SUV, and other models of high-performance pickup trucks. Isuzu’s diesel engines have won a long list of awards in the past years including “Truck of the Year” by Motor Trend Magazine, “Executive Diesel Car of the Year 2002″ by Diesel Car Magazine (a European magazine) “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.” What’s more, Isuzu vehicles were voted the top medium-duty truck brand six times in seven years by truck dealers. Remarkable, but still not fully convinced that diesel is way better? Keep on reading.

Diesel fuel, in point of fact burns much more efficiently than gasoline, thus giving you a better fuel economy; approximately thirty percent more efficient on average. Why?

An engine running on petrol uses the Otto cycle in which a fuel/air mixture is ignited by a spark plug. The air and fuel mixture when ignited by a spark burns and thereby expands to force the piston down. In case of a petrol engine, fuel and air are pre-mixed usually before compression. Earlier the pre-mixing used to be done in a carburetor but now (except in the smallest engines) electronically-controlled fuel injection is used for this. The pre-mixing of fuel and air makes a petrol engine to run at a much higher speed than a diesel. On the other hand, it severely limits their compression, and thus efficiency.

Diesel is denser than its unleaded rival. Proponents of gasoline are quick to point out that diesel engines generate 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. Also, because diesel engines use the more efficient direct fuel-injection method (fuel injected directly into cylinder) compared to the port fuel-injection setup in gas engines where gas is mixed with incoming air in the intake manifold, the diesel system has little wasted or unburned fuel. Diesels also use about one third as much fuel at idle as gasoline units. Even though there are no official EPA-mileage figures for the three and four ton and larger trucks, we’ve seen diesels get six to eight more mpg than similar-weight gas pickups. Over the life of the truck, this advantage could be significant, especially if you drive a lot of miles.

Diesel engines present better fuel efficiency when match up to petrol owing to the fact that they also have a higher compression ratio. Another benefit is that, a diesel engine can be more easily turbocharged than a petrol engine because of the fact that if the compression ratio and the pressure in the cylinder are high during the inlet stroke, the mixture starts to burn too soon, while the piston is on its way up. The diesel engine has no fuel in the cylinder and thus allows the turbocharger to suck as much air as it can without creating an issue.

OK so, this was definitely not the case with the old man’s wagon. Those days, before the anti-diesel movement, diesel engines were generating far more emissions because they plainly weren’t efficient.

But that’s not the only thrilling news about diesel. In the beginning, the diesel engine was created as a way to run vehicles using vegetable oils. While farmers in the beginning 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 the United States of America itself. These “hybrid diesels” also known as “biodiesel” are well-matched with existing diesel engines and can also be made from waste oils collected from restaurants or people’s homes—This is an option that serves several ecological benefits at the same time. These days, with the contemporary diesel engine achieving a twenty to fort percent better fuel economy, it’s time to give diesel a second chance.