Clett, what that table does not show is the horsepower for the gasoline versus diesel versions. In most cases, you have to give up power in order to get the diesel version of a vehicle. Thus, it's not just a pure gain in fuel economy; you lose power to gain fuel economy. As such, in theory you could just use a smaller gasoline engine that has less power to improve fuel economy, so it's not really apples to apples most of the time.