Let me add:
it will pull the entire Heavyweight train that was special made for it from K-Line cars: Express reefer, baggage, combine, chair car, diner, Pullman, observation. On a flat surface, it will pull them around surprisingly tight curves just fine down to 042/045. It's grades on the tight curves that defeat the engine.
The limiting factor is NOT the motor but the lack of grip--without the tires, it slips.
So if you have a flat road or nearly so, the engine is quite good. Do not expect it to climb mountains pulling a long train.
I don't know how much the one you're looking at costs, but I wouldn't sell mine for a lot more than I paid for it.
