Oil pressure is highly dependent on oil temp and rpm. I use 5w30 Mobil 1 full synthetic and cold starting pressure is 100 psi. at idle. Hot idle pressure is 26 psi. Hot pressure at 2,000-2,200 [ typical interstate speeds ] is 80 psi. Hot pressure above 4,000 rpm is 100 psi. I believe these rather large swings in pressure compared to older engines is due to the combination of relatively thinner oils and the fact that unlike older pushrod designs the oil pump is driven directly off the crank. The older designs drove the oil pump off the cam drive so like the cam they ran at one half engine speed. FWIW both GM LS series engines and the 3 rd. gen Chrysler Hemi's also drive the oil pump off the crank even though they are both pushrod engines.