According to this report/pressie, the algae-derived biofuel is cleaner to produce, burns cleaner, and that makes it a logical choice to use. 85% less greenhouse gas emissions may be a very optimistic evaluation, but remember that the bulk of the world's pollution load comes not from the humble car, but from trucks, trains, ships, power stations, and aircraft. And they burn diesel, in many cases...
Before you stop me on the power stations, I know that a lot fo the world's power stations are on coal (which BTW is far dirtier than diesel, even - and especially - the mythical so-called "clean" coal) but there are countless diesels ponking away around the world today 24/7 generating energy for smaller off-grid towns and farms, for isolated villages, and all of them would benefit from a cheaper cleaner source of fuel.
I think it's also high time engine manufacturers started looking into engines that aren't just standard Diesel or Otto cycle engines, and started tuning their existing designs to run better on biofuels. It's no longer a matter of being the coolest kid on the block cos your technology works more efficiently - it's now a matter of life and death...
