What do you guys think is more environmentally-friendly? Nickel mining and processing is one of the most polluting industrial activities known. It also happens to be the primary substance in most current hybrid battery packs.

Diesels, even with after-treatment systems, produce a relatively high amount of NOx and particulates compared to the cleanest gasoline engines, but get 30-50 percent better fuel economy.

What do you think is the "greener" technology?  

With the advent of higher tech particulate filters and the use of urea technology to offset the higher carbon dioxide output of diesels, I would have to vote for diesel technology. Add in the higher gas mileage with the promise of near instantaneous torque delivery from most modern diesels and you have a grin inducing driving experience. I also prefer having full use of my trunk space! No having to make room for a trunk full of batteries with a diesel engine.
   This last point is a little off topic, but I wonder why such a high proportion of hybrid owners insist on putting their life or political philosophy on a bumper sticker. In my eyes they are the modern day equivalent of the VW microbus. Name the last time you saw an old Microbus WITHOUT any bumper stickers. Never trust an individual who can fit their world view on a bumper sticker.  

Is this the right question to be asking? Surely a hybrid diesel is the answer? Just think of it great torque when required and high mileage. Marriage made in heaven? Does anyone have any ideas on whether this is being worked on and the likelhood of it happening?  

diesel. you can eventually switch to biodiesel which smells like french fries    

I would argue a hybrid is more environmentally friendly, as there aren't many small diesel cars sold in the US, besides the VW Bug and Jetta.  Mostly just big trucks or Mercedes sedans....  

nosmo.king:
Is this the right question to be asking? Surely a hybrid diesel is the answer? Just think of it great torque when required and high mileage. Marriage made in heaven? Does anyone have any ideas on whether this is being worked on and the likelhood of it happening?

In a perfect world, yes. But have you looked at the cost of the diesel option on the 3/4-1 tons lately? $7,000-8,000!! Add another $5k or so on top of that for hybrid, and you're looking at more than an Aveo's worth of an option! Sure, you'd get some takers, but would you get enough to justify the cost and investment? Not so sure. So is a diesel hybrid possible? Absolutely. Does it make sense economically? That argument's a little shakier.