Flow question?

[gwdriver]

I am using Mobil 1 10w30 in my truck. Nissan dealer here in N.C. uses 10w30 conventional. Owners manual specifies 5w30 conventional. I think I am fine using synthetic 10w30 because it's flow rate at start up and in cold weather is better than 5w30 conventional. Here is my question. Mobil 1 10w30 does not shear off at high temps like Mobil 1 5w30. Should I continue using Mobil 1 10w30 or switch to Mobil 1 5w30 at my next oci?

 

[drivewaytech]

I see no particular benefit switching to 5w30 especially during the summer and fall months. Your likely to experience no significant difference during the winter months staying with 10w30 in your region. However, I would stay with the 30W oil as specified by your owners manual, those auto techs know a thing or two. The lesser amount of VII's will aid in shear rate.