2-8-0 starting voltage

[Irbricksceo]

Hey all, So, i was just curious, of all my locomotives, one of my 2-8-0' has a ridiculously high requirement for motion. My 2-8-2 and 2-10-0 (sound) will start crawling between 2-6 speed steps w/o a load. the 2-8-4 needs 19-24 and another 2-8-0 needs around 27-32. But my other 2-8-0 doesn't start moving until it hits a whopping 57 speed steps, almost half throttle. It still retains the original starting voltage CV (though I don't recall the number at the moment) and I just think that's unusual, anyone know why that would be?