Good..
"Oil pressure is caused by the resistance of the oil to flow (viscosity) under the pumping action of the oil pump. With wide oil galleries and low viscosity oil, flow would be rapid and oil pressure low - a very desirable condition for minimizing wear. Conversely, under the same pumping conditions; with narrow oil galleries (by design or by blockage) and high viscosity oil, the oil flow will be slow & oil pressure will be high,"

 

Just explaining your quote that oil pressure and viscosity are not related is blatantly false.. just untrue whether there is a minimal difference or not.

Care to explain why our oil pressure at cold start is so much higher than when fully warmed up? Viscosity of the oil is thicker at cold starts - hence oil pressure being higher

 

I'll get it.

A 0(zero) weight oil, will have a certain "thickness" or viscosity at 0C and another "thinner" value at 100C.

A 40 weight oil, will also have a certain viscosity at 0C and a lower value at 100C.

The 40 weight at 0C, it's "thicker" value, will be HIGHER than the 0 weight oil at the same temperature, 0C. So at 0C, the 0 weight is THINNER than the 40 weight.

When the temperature is 100C, the 40 weight is still thicker than the 0 weight at the same temperature. So at 100C, the 0 weight is THINNER than the 40 weight.

Multi viscosity, 0w40, means that at 0C, it's as thick as the 0 weight at 0C, and at 100C, it's as thick as the 40 weight at 100C. At any given time, the oil of either weight at 100C is thinner than either oil at 0C.

To really illustrate this, I'll use some made up values:

0 weight @ 0C, 100 (made up viscosity number)
0 weight @ 100C, 0

40 weight @ 0C, 120
40 weight @ 100C, 20

0w40 @ 0C, 100 (0 weight value)
0w40 @ 100C, 20 (40 weight value)

*Remember that these are made up numbers to illustrate a point.

 

hmm i was under the impression that mobil1 5w30 also had pretty good oil analysis numbers . . . how much better is the 0w40 ? how about mobil1 0w30 ? ? i know gc 0w30 is good but im more of a mobil guy

 

^If you read the oil analysis for DE and HR engines, Mobil 5w-30 is subpar comparing to GC 0w-30, Mobil 0w-40, or Amsoil 0w-30. Amsoil 0w-30 probably has best results for both DE and HR engines.
Since you live in FL, Mobil 0w-40 would be your best option imo if you like to stick with Mobil.

One way to find out what is good for your engine is do an oil analysis.

 

got it . . gonna return the 5qts of 5w30 and get 0w40 . . thanks

 

I've been running M1 0w40 and have similar pressure readings to the OP.