weird oil pressure problem???

[Mad Mike]

I finally got to 1000miles on my rebuilt motor. I changed the break in oil out and now my oil pressure at idle after the motor heats up is only 11psi??? At 4000rpms in 4th it sits at 30-35psi and goes up the harder I drive it. I used Mobil clean 5000 10w40 and a STP oil filter(10.99 deal at autozone)

Before I changed the oil and filter I was running pure guard ND-30 non detergent motor oil and a microguard oil filter. Oil pressure at idle at temp was around 20psi and around 40psi at 4000RPMs in 4th.

What would cause a 10PSI drop? Should I swat out the oil filter to see if the oil pressure comes up?

PS: I also hooked up my mechanical oil pressure gauge to make sure my digital gauge was working right. I got the same PSI on both gauges.

Thanks for any help.

[1civic]

Change the filter..

[Mad Mike]

put on a fram(all I've ever used and the oil pressure at idle at temp (no driving yet) looks good. Going to take it for a test drive in a while.