at exotic materials like lightweight aluminum. you will have to look at more exotic strategies within the engine to save fuel, possibly different fuels. it can get expensive depending how they do it, it is possible, gary to build a much more fuel efficient car if you use very lightweight, space age materials but it is expensive and somebody has got to pay for that. exactly. the operators of the trucks will decide if it is worth it or not. if you can save 10, $20,000 a year in fuel, that s great if it didn t cost you $30,000 to get there with new technology. we ll have to find out how much this is going to cost. jon: the american trucking association, joseph, is out with a statement saying, ata hopes the administration will set forth a path that is both based on the best science and research available and economically achievable. those last two words seem to be the key here, economically achievable. well that s absolutely right.