I recently changed my oil. I was running Royal Puple 5W-30 synthetic and at hot idle I would run 40 psi. Yet now that I changed to German Castrol 0W-30 syntec I know see 25-32 psi at hot idle. Is it bad that I dropped this much pressure??? And what exaclty does lower psi mean, flowing slower, lubricating the engine less??? Im in Houston, seeing 95-100* heat. I have a 160* therm and dont see above 190* coolant temps.

Edited to Royal Purple, I wasnt thinking right when I posted and stated I was using Mobil 1.

 

going by the books....10psi for every 1000rpm is required for proper lubrication, your oil pressure is fine for the engine being at operation temp....but why did you choose 0w30?...for that temperature i would use a 50 weight oil...i use 15w50 mobile year round, i have no problems.....alot of people would tell you and me that 15w50 is too thick, but i have 220,000kms on mine and it runs perfect......thats just me opinion

 

0-30w oil is way too thin for this heat. the viscocity needs to be thicker on startup and thicker when warm as well. I live in houston as well and during the summer i put in 10w40 and in the winter i put in 5w30. I think im gonna go ahead and stay with 10w40 year round though now because our winters arent really that bad. Brand and oil weight will give you different oil PSI readings. As long as your PSI jumps up when you rev it you are good to go(average of 10psi per 1000 rpm's like mentioned above).

 

Did you change the brand of filter, some filters are a lot more restrictive than others.

 

QUESTION...i use o-40 mobil with the k&n filter...is the oil still to thin

 

IMO, the thicker the oil, the better, I use Mobil 15w-50, and I wouldn't dream of using something like 5w-30. Way too thin.