Oil Viscosity and density Question

[JimKellyfan]

I think they all use 5w30, do they not ?
The numbers can be thought of in how they pour at what temp, really.
Picture cheap vegetable oil and its thinness, then filipio barrio olive oil and its thickness.
5w30, is a 5 weight oil (or thinner) at 0 degrees centigrade and a 30 weight oil (thicker) at 100 degrees centigrade.
And so on.
So, picture cold start up, one would want a thinner oil then, to minimize damage until the oil defies gravity with the pump.
Toyota went to 0w20 eventually, except where they had more performance or heavier duty applications and stuck with 5w30 on those.
My opinion, I think Toyota is paying less disposal fees on the sale of each car now that they recommend an oil change every 10k miles with 0w20.
But, another benefit of the lighter oil is fuel mileage.
0w20 and its benefit on fuel mileage is there, but, my opinion, not worth it.
I would go with 5w30, or if you are abusing it, maybe 5w40 and full synthetic.
I will never go more than 5k on my oil change, and keep an eye on what it looks like on the stick and change early if it appears to be breaking down and/or dissipating.
Make sure to, to stay the same or higher rating as well (SM, SN, SL and so on)
That is a quality (how many chunks of crud) grading.