On the railroad the big concern is tonage miles per gallons. If you apply this to a 7200lb Mega cab at 19mpg and a 2765lb Prius at 48mpg the Megacab is moving 1 ton 68.4 miles on one gal. The prius moves 1 ton 66.24 miles on one gal. Now which one is more efficient ? I think i just became a tree hugger. By the way the Union Pacific Claims it avg 1 ton over 600 miles on one Gallon.