I bought LIQUI MOLY MOS2 LEICHTLAUF 10W40 and Ceratec from jaesern. He's a very nice seller.

I was previously using Petronas Synthium 800 10W-30 on my Persona Elegance with NGV. Now LIQUI MOLY MOS2 LEICHTLAUF 10W40 and Ceratec.

Since it's a new car, there isn't much idling noise to start with, so they are both just quiet. The noticeable improvement is during the drive. Low end acceleration is fluid and smooth. Cruising is even smoother with the reduced friction by Ceratec, the car just glide through. I practically lift up my foot frequently on the highway