If the store says so, there's a chance they'll run okay on 18" track. I just speak from the experience of someone I used to know, who had a model of Douglas that was prone to derailing on his layout, I believe the curves on his layout were around 18", but I'm not 100% sure.
With that said, since I don't own Donald or Douglas, I can't speak from experience with these models, as to how well they'll perform, I'm just advising caution based on other people's experiences. Perhaps someone else would be better able to speak about this subject. My advice is to just be cautious
~Alex
With that said, since I don't own Donald or Douglas, I can't speak from experience with these models, as to how well they'll perform, I'm just advising caution based on other people's experiences. Perhaps someone else would be better able to speak about this subject. My advice is to just be cautious
~Alex