$2 per day verses SUV - who do you think will win?
5p extra is fine for you, but what about the sizable chunk of the world that is on a dollar or two per day? The corn required to fill up the fuel tank of an SUV just once would feed a person for a year.
It's poor people vs the SUV - guess who's gonna win?
Every acre of land converted to biofuel production is an acre of land withdrawn from food production. And those left hungry will do whatever is required to get food; I certainly wouldn't want to be standing in their way. So they will convert whatever undefended land they can to food production. The only undefended land left in world suitable for food production? The remains of the rainforest in places like Borneo and Brazil. So biofuels will be the killing blow to the world's remaining rainforest.
And once we've eaten the rainforests, what then?
Flame? - Cos thats what you use to clear forest for food.