Of course "specific energy". You're either unaware a train is significantly more massive than a car, or you're deliberately trying to mislead with your statement. Neither is encouraging.
I would say that focusing on the total big number is deliberately misleading. When the goal is to accelerate (decelerate) mass using the friction created by the weight of the mass itself, the amount of mass cancels out. Likewise when the goal is to transport mass, then cost per unit mass is what matters.
As I said in another comment, we don't condone SUVs or tractor-trailers ignoring red lights just because they're heavier.
As I said in another comment, we don't condone SUVs or tractor-trailers ignoring red lights just because they're heavier.