I bought a used Certified 2018 manual S with only 6100 miles. Love the car but I think the original owner must have lugged the motor and trans by shifting up too early. I can barely hear a bit of what sounds like output shaft bearing noise if I put it in a taller gear at low speeds and nail the throttle. My thinking is that a higher quality gear lube will help on all counts, worth a try anyway. Any recommendations? Brand and grade please. Did a search but couldn't find what I was looking for.

 

OEM is a top quality product.