Does anyone know about Mercedes Benz Bluetec technology? It's apparently a clean burning deisel technology that allows the MB's heaviest car, the GL, to get 24 mpg.

Bluetec is actually an emissions reduction system. Diesel engines are generally more fuel efficient than their non-diesel counterparts, but diesel engines are notorious polluters.

From Wikipedia.com...

BlueTec is Daimler AG's name for its two nitrogen oxide (NOx) reducing systems, for use in their Diesel automobile engines. One is a urea-based reductant called AdBlue, the other is called DeNOx and uses an oxidizing catalytic converter and particulate filter combined with other NOx reducing systems. Both systems are designed to reduce pollutant emissions.

So Bluetec is used to improve diesel technology. Car manufacturers are able to get the best of both worlds, the high fuel efficiency of diesel without the harmful emissions.

This technology is not only available on the high-end Mercedes Benz, but also other cars of the Damien Chrystler family, such as Jeep. Hope this answers your question.

Not quite that simple, as diesel still has high emissions. Bluetec lowers the emissions compared to other diesel engines but it is not as clean as the cleanest gas vehicles per gallon of fuel burned. The advantage of diesel is that it contains more energy and therefor a vehicle can travel farther on every gallon burned. On a emission per mile basis diesel is good but whether you purchase one depends upon your use. Country or highway driving brings deffinate advantages, while city driving minimizes those advantages since the engine is rarely fully warmed up and emissions controls do not work properly until they are at optimal operating temperature.

Thanks for the info. Do cars that run on bio-diesel or recycled vegetable oil have similar emissions as cars using regular diesel? Do bio-diesel and vegetable oil fuels also only have better emissions than gas on on highway or country roads?

The emission are lower in all categories compared to petro-diesel except nitrogen oxides which can be raised a small amount. What you have to remember is that these polutants are coming from renewable sources and that the plants that grew to make the biodiesel/veggie oil fuel sequestered them in some form while they grew. Overall the net effect is that some particles are created only when burned which are not absorbed by the replacement plant material and you are adding them to the atmosphere, but in my opinion this is much better than using a non-renewable sequestered fuel like petroleum to do the same job. The major disadvantage to biodiesel or veggie oil is sourcing. There has been great controversy for a few years now about massive swaths of land being cleared in the Amazon basin to plant palm for use as biodiesel. This land used to be cleared for corn production and the Biodiesel is not to blame, the land would be cleared anyway (unless we all decide to really do something about it) but it is something to consider.

I considered the idea of biodiesel/veggie oil fuel when I bought my last car. My problem was that since only limited Diesel vehicles were imported to the U.S. in the last 30 years there is a short supply and the prices are grossly above the true vehicle value. 1980s Mercedes Diesel cars are selling for $10,000+ which is about twice what the gas versions sell for. Volkswagen has the Passat, Beetle, and Jetta from the late '90s and early 2000s but again these were too expensive for the return. I ended up buying a Saab with the turbocharged 2.3L gas engine which was the first car sold that actually puts out lower emissions at the tailpipe than the air being drawn into the engine in dense environments. It actually cleans the air (not really, but you can technically say so). The best thing to do is not to drive, but seeing as our country is set up so that driving is a necessity in most places this is not practical. e-mail me if you want further info, like.i.amuse.you@gmail.com my name is Kevin. Also check out: http://www.biodiesel.org/resources/faqs/