yea you guys are probably right, even with the thousands of fast food restorants in the united states that use gallons, and gallons, and gallons, and gallons, of cooking oil and just dump it, however there are Tuns of fast food restorants in the united states and each of them use Gallons.... of oil at a time, there are thounsands of Mcdonalds, burger kings, Wendies, Arbies. you have your Chinese restorants that deep fry a lot of there food. that is a LOT of fuel! and it has its downsides too like getting thick when it gets cold...

but Hidragen as a fuel of the future... im not too sure... i mean yes it burns real clean, but is it easily renewable. i mean the advantage of Biodiesel is it is literally the byproduct of the food we eat. and does it offer a practical range... it may work fine in Europe were getting from one country to another is just as far as driving from one state to another here in the us...  i mean i remember seeing this Show on TV where this one guy had to drive some 500 miles or so and he had to put these massive tanks in the back of his truck just to get that far. when with the fuels we are already using it just means re filling the 10 15 17 20 gallon tank you have in your car or truck, and that will give you some 200-300 miles to drive... also what about re fueling, yes just get a new Tank, but wont that get expensive after a while, and will it be convenient? in addition you stated it burns cleaner than Biodiesel, but... Biodiesel does actually burn quite clean... it burns very clean compared to normal patroliom based fuels beacuse its composed of few hydrocarbons.