My 8120 has used oil since new. They replaced the turbo last year which helped considerably but I'm still concerned its using more than normal. So far this year in 100 rotor hours its about a half inch from the add...is this about normal? It has just under 500 engine hours at this time. To me this engine smokes too much. Occasionally you can be stopped to unload and it will have a faint stream of black smoke. If you put a pile through it you will definitely see a good sized puff of black smoke. My old 8010 used almost no oil and could run inside the shop. This 8120 could not be run inside a shop. Crankcase breather has also be changed 3 times now. Is this normal or can you offer any suggestions?