Different Oil Pressure, Bad Gas??

[ddeadserious]

I just got a 4.0 out of a 94 ZJ with 120,000 swapped into my 93 XJ a few days ago. It's been running great since, with 50 psi of oil pressure at idle and when warmed up. Then last night, I put gas in it, from Fusion Oil Company, new no-name gas station in town. Usually I go to a bigger name one, but it was on the way home, and it was reasonably cheap, so I went there. Didn't notice anything on the way home, it only a half mile til home, but today, I drove about 20 miles. The oil pressure gets to about 45 when moving, and about 20 at idle. It also idles a little rougher than it has been. Could this be because of bad gas? Should I siphen it out and put in good gas?

[old_man]

Different gas will not make a change in oil pressure. Your oil pressure is well within the factory specs.

[ddeadserious]

Alright. But why would my oil pressure change overnight?

[MrShoeBoy]

How are you reading oil pressure? If you are going by the factory gauge then by all means it will change over night. If you want accurate readings, run a mechanical gauge. The readings you have are well with in spec just like old man said. The running rough could be bad gas. Just throw in some fuel cleaner and a few gallons of good gas and everything should be fine.

AARON