If this is the set with Bachmann’s 4-6-0, you probably will be satisfied. That engine is nicely designed with low-speed gearing. And it’s not strictly a train set locomotive, given that it is sold separately.
However, I have never run my Chesapeake and Ohio version with more than five cars, so I don’t know what its top limit is. It’s a diecast model, so weight isn’t an issue.