Mike Brown (mikebrownsolutions.com) has been writing about alternative energy for a few decades now .... he played with the numbers and thinks there is enough unused or underutilised farmland in the US to raise the raw materials for alcohol (an easy conversion for gas engines) and veg oil (BD or straight) to run all our engines -- within 3 years. BD300TD reminds us that farmers use diesel -- but those engines could also burn WVO or BD. I agree with Charlie M -- we might not get all the way to self-sufficiency -- but we could try. Substituting grown fuel for 50% of the road fuel and home heating oil currently consumed in this country would make an immense change in foreign policy, lop off a lot of the payments currently going overseas, & create a lot of jobs here. What's not to like (unless your name is Exxon or Mobile)?