Oil pressure before and after oil change...

[Mark Francois]

Hi folks, this is my first post here. I’ve got a question about amsoil and oil pressure. Ive got a 2003 GMC Yukon 2wd 4.8l v-8 with 114k on the odometer. Ive been running Amsoil XL with an amsoil filter since about 70k miles, changing every 5k miles. What I’ve noticed is that before a change I’ll have 40psi idle and at speed at start up and 25psi idle 35psi highway speed At operating temp but when I change oil I’ll be about 10psi higher at idle and at speed. The truck doesn’t burn any o il between changes and runs like a sewing machine. What the reason for the pressure drop after 5k of use? And should I switch back to castrol where I didn’t notice this issue??

Edited January 16, 2020 by Mark Francois

[sefiroxx]

Break down of carbon chains

[Mark Francois]

I wonder why it only does this with my yukon? It doesn't do that with my gas burner F250, Ram, Camry or the Armada... only in my yukon. 
 

[sefiroxx]

Different motors, different temps, different results