Reply #14: Does Not Work For Bio-Diesel Either See Below From The Article

[mhr]

"In terms of energy output compared with the energy input for bio-diesel production, the study found that:
-soybean plants requires 27 percent more fossil energy than the fuel produced, and
-sunflower plants requires 118 percent more fossil energy than the fuel produced."

Now to your point on fuel economy, there was a post on DU back during Katrina that listed over 50 models of European autos that all had 50 mpg fuel efficiency.

So yes we can move toward better fuel economy but that will only move the Peak of Peak Oil to the right. It buys us some breathing room but does not solve the fundamental problem of oil depletion.