Not sure about that. I just know they changed the color of the Trackstar sensored 2100kv from silver to Red for some reason. The 1/8 Trackstars look like the exact same motor as I have some of the newer red 2100kv motors here they are just red in color like the 1900kvs.

I haven't used but one of their 1/10th motors so I can't comment much on those. I'm sure someone on here has though.