There is no reason to ever run a single grade oil. It’s not 1955 any more.
Those who advocate against synthetic oils (good synthetic oils, not that **** the “supreme” court says is synthetic) have never actually tested anything.
Synthetics do everything better. Everything. I’m not talking about over the counter Group III base oils, I’m taking about Group IV and V base oils, and most likely a blend of the two.
With a synthetic you can use a different and better additive package, and you can use more of it. It will last longer for that very reason. The base oils don’t “wear out”, the additive package gets used up.
Oil analysis is cheap and effective.
The only drawback to the synthetic is upfront cost.
