On some sets, a economy version was available along with a standard version. The economy versions had a -4 at the end of the set number to designate 4 wheel cars. The standard set had -8 to indicate 8 wheel cars. Here we have a 10711-4 and a 10711-8. I normally stay away from the 4 wheel sets, but this one had the red Marlines steamer that I like so I went for it. Also note that for some reason my 8 wheel set came with a 4 wheel flat car. Go figure.
Steve
