The gear oil in my car has not been changed since I bought it in 2014. This is a 2008 350z. It got caught in a flood and the insurance paid for another engine. The second engine worked better than the old one. I kept up with regular oil changes but only added gear oil when needed. I've always used Castrol Transmax Multi-Vehical and found it good enough. In the end, a burning smell began to emanate from him. In June 2020, I decided to spend enough money to buy a Nissan-branded Matic S. I had the mechanic change the transmission oil. I've noticed a big difference in the gearbox since it's filled with clean oil. This genuine gear oil is a good thing. I was too cheap to buy it before. Now I will use what is recommended for my car.