So I saw one post about this and started a post myself which went unanswered. So I figured no one has bothered to try or doesn't currently have a 3 1/2 year old obsessed with trains in general and Polar Express. IDK. But I went ahead and got the Lionel Polar Express running on M track. Each car has its lights running. I did change the coupler from the 1st car to the Marklin 3091 4-6-2 tender (which acts as the PE loco), Added a battery operated switch for each individual car for the lighting, and replaced all the wheels with a marklin wheel of the same axle length but with a slightly larger diameter and a bigger flange. You need that flange big time for curves and especially if you have a adjoining turnouts and so on. That is a must do. I am using the Lionel provided couplers between the 3 PE cars themselves. They have worked , Ill say well so far. Could be better.

Ill post the modification after Xmas. I documented with pictures everything i did. It was fun and i certainly learned a few things. I just have one quick snap shot of the lighted cars on the track currently. Its hard to get in my sons room to use the track with him not in there. Lol.

Quickly I'll say this though - The Lionel PE trains cars (not the loco) are made in china, and are rather cheaply made, Go figure. Outside looks great, But for Lionel they feel dinky compared to an older car, which i expected. When taking apart these trains and comparing them to the older Marklins, which I have, Your just left feeling that as trains advance in Tek and digital Loco's/tracks - that Marklin really makes just much more solid and comprehensive, Track and engines etc..

Mod Build to be posted soon. Unless I don't see any interest, i wont waste Forum space.

Thanks all
Mike

I hope your 3-1/2 year keeps up the interest in trains and may your family have a Merry Christmas!