- Joined
- Apr 13, 2013
- Messages
- 3,263
I posted some time back about returning to 5W30 after a one-time run of M1 0W40 in my Infiniti. I had a jug of QSUD 5W30 that I used up and the engine's noisier now. It wasn't this noisy when I ran 5W30 during previous winters. What could a one-time run of 0W40 have done that caused this to happen?