Which is more environmentally friendly, a hybrid or a diesel?

Question

Which is more environmentally friendly, a hybrid or a diesel?

Answer 1

If you're considering mid-size cars available in US market, a straightforward comparison would be Prius vs Jetta TDI. The fuel economy of the two is comparable: 49mpg Jetta to 55mpg Prius.



The tailpipe emissions for the Prius are cleaner, but using biodiesel instead of diesel fuel reduces those emissions to a significant degree:

http://www.epa.gov/OMS/models/analysis/biodsl/p02001.pdf



The anticipated longevity of the battery packs for the Prius is a point of contention, and even if they are replaced, that produces heavy metal waste of dead batteries to be disposed of:

http://www.greenhybrid.com/discuss/will-the-battery-of-the-prius-i-last-the-lifetime.534.html



It is clear, however, that the lifetime of the car is claimed to be 100k-200k miles for the Prius, whereas the Jetta TDI very commonly lasts 300k-400k miles. Given the tremendous resources consumed in the manufacture of any new vehicle, the vastly greater durability of a diesel far outweighs the slightly lesser fuel economy.



The better question here should be "Which is more environmentally friendly, two hybrids one after another or a single diesel?"



In Summary: the more ecologically responsible _and_ economically feasable choice is a diesel. (And it's even clearer win for diesel if you're powered by biodiesel or vegetable oil)

Answer 2

A hybrid vehicle is still much cleaner than a diesel, since diesel fuel doesn't burn as completely as gas. Mercedes-Benz is experimenting with a new diesel emissions system (urea injection) that has to be refilled every few thousand miles that provides comparable emissions to gas.



Most hybrid vehicles are classified as AT-PZEV or Advanced Technology Partial Zero Emission Vehicles. In addition, california hybrids often adhere to the even stricter Tier 2 Bin 5 standards, which means the hydrocarbon emissions from a Prius or Civic Hybrid are less than that of a small pine tree. Of course, all combustion results in CO2 (greenhouse gas) but in terms of smog forming pollutants hybrids are better.



However, the battery pack is still a big concern for some. If they are recycled when they wear out, then hybrids win flat out, but if not.. then it gets more complicated.

Answer 3

A hybrid, because diesels emitt cancergenous causing gases.