On Tuesday, November 7, 2017 at 1:48:52 PM UTC-5, The Real Bev wrote:
> I grew up on 10-30 or 20-40. This is SoCal. No freezing, lots of heat.
> Synth oil is nice, but expensive. The concept of 0-20 oil, although
> the manufacturer suggests/demands it, is just alien. We never freeze,
> we just have to worry about the oil thinning out when the ambient is
> over 100F.
>
> I assume I'm worrying needlessly now, but I'd like to know why.
>
> --
> Cheers, Bev
> It's 95% of the lawyers making the other 5% look bad.

Today's motors have tighter tolerances and need thinner oils to keep things lubricated.