T. Boone Pickens is making a new pitch for natural gas to be the fuel of the future, especially in America’s big rigs. However, while declaring natural gas as the only replacement for petroleum diesel, the billionaire oilman seems to forget that biodiesel is already a great source to replace petroleum-based products… without having to convert any engines.

In the latest video from Pickens, he goes “back to the whiteboard” to make the case that out of the 21 million gallons of petroleum used each day in the U.S., 13 million gallons come from imports, and 5 million comes from the “bad guys” at OPEC. He says that 5 million is the real problem, as we are funding both sides of the war on terror with those purchases. Pickens proposes that if the 8 million 18-wheelers in this country were to run on natural gas, that would take care of 2.5 million gallons of OPEC oil each day, effectively cutting the oil cartel in half. He goes on to say that conversion could be done in just seven years.

But while Pickens makes a good case, pointing out how much cheaper natural gas would be than petroleum diesel (about one-fourth the cost) and how much cleaner burning it is, I think he steps in it a bit when saying that “natural gas is the only resource we have that’s going to replace diesel.” Biodiesel will run in any diesel engine, especially the big rigs, without having to change anything on the engines.

He does say that various biofuels, including biodiesel and ethanol, are also good for American cars. But I hope that not everyone takes his “only resource to replace diesel” comment too much to heart. Biodiesel is ready now.