>>9515890This was the best pic I could find on short notice so I'm sorry these aren't steam trains, but here's an example of 6 wide (Lego standard) vs 7 wide (What I usually build my trains in and what most European builders tend to build in) vs 8 wide (The scale most American builders tend to build in). Depending on what kind of trains you want to build, the scaling is all up to you, but from what I've seen it's easier to fit/hide electronics in 8 wide models than it is 6/7 wide.