This looks like a pretty good thread. Emissions testing is very important. I too would like to know which is better in terms of car emissions (not factory/transportation considerations):
Biodiesel 99 or 100, a "real" hybrid like the civic or prius, or waste veggie oil (WVO), which I also currently use for my formerly dirty diesel short school bus (yes, I wear a helmet).

I am v. excited about WVO because it cuts out all the "production factors" of biodiesel (even bidiesel 100). It is simple to collect and filter at home. Also, mind you this is for a school bus that holds approx 25 gallons of WVO.

thanks for the discussion.

2007 Honda Civic Hybrid
Bought in Valencia, CA
Sunday, Feb 18, 2007
I'm still in shock...