Oil Viscosity

[ctrlraven]

This isn't a debate about oil brands, merely a question about viscosity and oil pressure at higher temps.

Since it has gotten a lot warmer I have noticed once my engine has really warmed up and usually the coolant temp is 190 my oil pressure gauge reads 25 psi at idle (which I know is normal) but at cursing or blipping the throttle the psi does not increase and will read between 35-40 psi (line mark between 25 and 50 on real oil psi gauge). I have been using Mobil 1 5W-30 High Mileage for the past 2-3 years (used M1 0W-30 this past winter). I don't recall seeing the oil pressure below 50 psi last summer when I drove the car.

I know oil gets thinner as it gets hotter, my question is the pressure I am seeing at cruising or on the throttle when the oil is hot a safe psi or should I get a slightly thicker oil.

[fastblackmerc]

This isn't a debate about oil brands, merely a question about viscosity and oil pressure at higher temps.

Since it has gotten a lot warmer I have noticed once my engine has really warmed up and usually the coolant temp is 190 my oil pressure gauge reads 25 psi at idle (which I know is normal) but at cursing or blipping the throttle the psi does not increase and will read between 35-40 psi (line mark between 25 and 50 on real oil psi gauge). I have been using Mobil 1 5W-30 High Mileage for the past 2-3 years (used M1 0W-30 this past winter). I don't recall seeing the oil pressure below 50 psi last summer when I drove the car.

I know oil gets thinner as it gets hotter, my question is the pressure I am seeing at cruising or on the throttle when the oil is hot a safe psi or should I get a slightly thicker oil.
My oil pressure is around 25 when hot at idle, over 100 when cold. It's the same when I used 5w20, 5w30 or 0w30. When I blip the throttle the oil pressure goes up. Real oil pressure gauge.

[RF Overlord]

The rule of thumb is 10 lbs per 1000 RPM.

The 100°C viscosity of M1 AFE 0W-30 is 10.9 and that of M1 5W-30 HM is 11.7, so the HM oil would give slightly higher readings.