Hi BITOG, We have 6 Nissan VQ 3.5L in the family, Muranos (2) and Maximas (4 of them, 11, 09 , 03 and 02), and about 4 Honda engines between 3.5L and 2.4L (Odesseys and CRV), all Nissan ones run on synthetic 5w30 (Synth Pennzoil or Mobil1) same for the Hondas (only difference is 5w20 or 0w20). (side note: Pennzoil UP is much quieter than Mobil1 in all) ALL Honda engines are much smoother and quieter than the Nissan ones! especially when cold outside. ALL engines are meticulously maintained through out their lives! Does the Xw20 oil make engines run smoother or it just Honda charm (or Nissan timing chains)? Interested to hear your opinions!