There should be a lot of things that make trains more efficient. Here are some of my guesses: Hard tracks and wheels = less rolling friction? Less air resist

There should be a lot of things that make trains more efficient. Here are some of my guesses: Hard tracks and wheels = less rolling friction? Less air resistance since one leading car breaks the air for 100+ other cars? Engine can run at a constant speed Less changes in speed Less starts and stops Slower acceleration