Increases fuel consumption and decreases acceleration/braking to make trains feel more heavy and have a cost to running them.
Does not change the actual weight of trains.
Rebalances fuel stack sizes to have progressive total MJ (I'm looking at you, coke pellets!)
Biter evolution factor is set by progress through the research tree.
Adjusts ore stack sizes so on-site processing is a real choice
Reduces inventory sizes on vehicles to be more inline with trains