I drive a 2003 VW Jetta TDI - I get over 1000Kms per tank yet VW diesels are never listed as 'Green' - Why not

Question

You constantly see lists on MSN, Yahoo, Canada.com of cars that have the lowest 'Carbon footprint' and they are rightfully full of all the great new hybrids and small, efficient Japanese cars but my Jetta outdrives all of them in terms of overall efficiency but yet is never listed as a viable option alongside all of the hybrids that only average 650 - 800kms per tank of gas. At 1000 - 1100kms that I get with my Jetta the highly efficient diesel engine and the cost savings on fuel should be really pushed in North America. Why is diesel left behind when it is by far the most efficient in terms of distance driven by amount of fuel used.

Answer 1

Hi,

It does not seem like the number of km per tank is a good way to compare, since tank sizes are different.

If you go to www.fueleconomy.gov and do the "Find and Compare", the 2003 diesel Jetta manual is listed as 35 miles/gal city and 44 highway with 5.6 tons of CO2 per year.

It is well into their "Best" range, so they seem to think its a green car.

The equivalent gas engine Jetta is listed as 21/29 mpg with 7.7 tons of CO2, so its much better than the gas version.

A couple reasons why diesels are not quite as green as their miles per gallon numbers would indicate:

1) Diesel fuel has about 15% more energy content per gallon that gasoline, which is good and is a part of the reason they get better gas mileage.  But, diesel also have about 15% more carbon content per gallon, which leads to higher CO2 emissions.  So, in rough terms, a diesel might get about 30% better gas mileage than an equivalent gasoline car, it will only get have about 15% lower CO2 emissions.

2) Diesels have had higher levels of other pollutants -- like particulates.  In the US, the new low sulfur fuel requirement should allow diesels that are low in all pollutants.

Gary

Answer 2

Check out this page: http://autos.yahoo.com/green_center-fuel...

They are there.  I drive a jetta tdi 1998.  Nice car.  47 mpg!  You gotta love it.

Plus the new diesel fuel is much cleaner than that of just a year or two ago.

Answer 3

You're missing the point of what "green" means.  It does not necessarily mean a vehicle with the highest mileage.

More so it means a vehicle which produces the least amount of harmful emission byproducts per unit distance driven.

Sure your VW can get 600 miles per gallon, but burning the diesel fuel you used for that tank probably produced more pollutants than an equivalent gasoline-powered engine.

The Toyota Prius, for instance, gets 50 miles per gallon but the important thing to remember is that it produced only 10% of the emissions during that tank compared to the average vehicle of similar size.

Answer 4

I've heard of these clean running diesels. There is a new Lexus model that runs diesel like your VW and is said to be even cleaner than most hybrids!

Don't you think, because of the elevated price of gas and of the high amounts we use, that many people would be activly seeking to find atlernatives? I mean it would at least save an extra $15 everytime you fill up! The bottom line is, we are addicted to gasoline and oil companies, automobile companies, as well a the government are all cashing in on this and continue to feed us.

There is still trillions of dollars to be made in the oil industry, so of course they want to keep the demand for oil alive. Along with the government's involvement in oil business and the large car companies ties to both of these, theres great deal of will power behind the discouragement of ANY alternatives to gasoline.

The automobile companies have dipped their feet into ideas of alternates in the past. Their excuse for not capitalizing on it is that the demand is too low. Well of course, if your market doesn't know about any of the benfits of your product, then they would not buy it. If the large company wanted to sell something then they would MAKE a demand for their product. Thats what advertisement is all about. They did it (quite successfully i might add) with the Hummer series. (and those are some gas guzzlers right there!) If the consumers actually understood everything about the positive benefits of alternatives, then many people would drop their gasoline cars for something better.

And all this is not to even mention the environmental benefits of these alterantives! (No more smog; preventing global warming)

To answer your question, when it comes down to ANY alternative to gasoline (electic, hybrid, diesel, fuel cell), you are not going to hear anything close to a fair market assesment because "the man" (haha!) doesnt want you to know about it. Your Jetta is no exception...

Answer 5

Ben,

The reason is diesels use higher temperatures and pressures to create ignition without using a spark plug.  These higher compression ratios cause the 78% nitrogen in the ambient air to mix with excess oxygen (Because diesels are constantly running in a lean burn state, even under full throttle acceleration) to form more oxides of nitrogen (NOx) than gasoline engines do.

The 2007 Mercedes E320 Bluetec is the cleanest diesel ever produced, yet it still can't be sold in 5 states because of its emissions.

http://blog.wired.com/cars/2006/09/merce...

NOx is 298 TIMES more potent a greenhouse gas than CO2.

http://www.manicore.com/anglais/document...

This is the reason.  But soon you will see them listed as green cars as particulate matter gets reduced and advanced EGR helps reduce peak combustion temperatures and therefore NOx.

However, keep driving that diesel using biodiesel and help reduce dependence on foreign oil, and your fuel is then also a closed carbon cycle.

Answer 6

This is simple to answer. Most car companies predict what is considered a green vehicle to the consumer. The only reason that they choose not to include the diesel engine in this list is that they do not recognize diesel as a green fuel because of the abundance of this type of fuel in the market. Wen it comes to a gasoline engine you will find that the oil reserves needed to produce gasoline is at a low where as diesel, in the US is 90% bio diesel.

Answer 7

diesel engiens are very efficient in terms of fuel used.

they are not "green" because of the level of pollutants, especially PM10. PM10 is responsible for thousands of deaths annually.

Bio-diesel is "green" because it is can be nearly carbon neutral, so if you use recycled chip oil in your car it will be classed as green. They even try & label 8litre bio-diesel racing cars as green