Lancelot 37, In the case of turbine engines Its hard to say weather the new oils are behind the large extensions in TBO, however in the case of complex piston engines its plain to see {ie GITSO Conts} At O'Haul the lack of wear and carbon deposits are obvious even to the naked eye, thats the good news, the bad news is that a lack of sound operating methods by pilots with little or no knowledge of piston engines often undoes the good done by the new oils.