Originally Posted By: steve20
"""For synthetics, this is not the case. Synthetic never really breaksdown like conventional, additives just wear out. So with synthetic, use the lowest starting grade specced. In your case its 5w30"""
WHAT THE ?
This is entirely false information!
Ever seen Mobil 1 0w40 viscosity after 5K tough miles?
The oil itself never wears but but the VII that are in the oil can degrade causing it to become a 30wt after a few thousand miles.