Thanks for the responses, I was wondering about the break in period also. How many hrs do you guys think would be enough? One other question, I use gunk engine flush in my car and truck engines prior to oil change, we have a ford escort with 300 thousnd miles on it and I asways flushed it. When we had to put a new head gasket on it the machanic told me that he had never seen the inside of a engine so clean, he said it looks like it only had 10 thousand miles on it, compressin is still great he said. Would it hurt to add a little engine flush to my Kholer command prior to oil change in it?