aquajr

Temperatures have been consistently over 100 for the last 2 weeks and I'm due for an oil change. I will be using Amsoil since I have the preferred membership. While living in California I was running 0W30 Signature Series year round.

Should I use 10W30 during the hot months and switch back to 0W30 during the winter when the highs are 50-60 degrees or should I just stick with 0W30?

Z28KLR

Either one would be fine all year long, as it really doesn't get that cold in LV. Given the choice myself I would probably just keep it simple and run the 0/30.

moncherou

Stick with 0w-30. The first number means that your oil exhibits properties of 0 viscosity oil when cold, And the second when warm. So, moving to a 10w means the oil is slightly thicker when cold which means that upon a cold start in the morning, The oil doesn't flow as freely. It might not matter much but unless you see 10w-x in the manual described for certain hot conditions, I would not do it.