Some research (I’m definitely not a rail expert) indicates that oil tankers are pretty heavy per car compared to typical freight cars. So the “typical” tanker train is pulling the max weight that the locomotives can handle for the grades to be traversed at the speeds required.
Not busting your chops, nas.
There are some truly immense tonnage coal trains that have 3-5 locomotives at the head end with a few more mid-train and a couple more at the end (remotely controlled). Of course, these are unit trains that pick up at the mines and deliver to the customer without picking up general freight at every Bugtussel siding.
That being said, leaving cars full of minivans at a siding makes no sense. Unless someone wants to send a message to the manufacturer of them. Ciao.
/tinfoil.