I have researched it many times on internet, Company has made it very difficult and technical to change CVT oil, coz they never want to change it in Approximate lifetime of the car. In old cars Auto tranny oil was recommended to be changed at 40K kms, not in CVT. So lifetime of the car is calculated 250,000 Kms or 10 years whichever comes first. But if u feel any problem in CVT like Jerks, or Gear slip, then u can change or check it earlier. And i am satisfied with this research. I have seen 2001 vitz with genuine gear oil, No issues at all. Mine is 2006 74k on ODO, genuine CVT oil, Alhumdulillah.