To JD-Rod:
I have 3 Lionel AC6000s, Union Pacific, Santa Fe, and C&O Chessie System models. My layout uses both 048 Fast Track curves and 036 Super O curve track. I have run each of these models on the Super 0 track 036 curves. Many times manufactures will list what they believe is the correct minimum curve before a new model comes out and sometimes we find out later after a new model comes out that that locomotive will operate on sharper curves. Sometimes they will make a correction on the box label and catalogs such as the Lionel Genset Locomotives that were at first listed as minimum curve 042 but in the second run they changed to minimum curve listing to 031. By the way the AC6000 is a nice looking locomotive model that operates very nice as well. I had only planned to purchase the Union Pacific model but when I saw the Santa Fe model on display at my local train store I just had to have it. The Chessie System model was offered by Lionel for sale at $300.00 with free shipping so I could not resist it for that price and I really like the way the locomotive is painted.
Ed Gerson